From 3481ed1eee9bbdda77435d2c5f698c714ea2fea3 Mon Sep 17 00:00:00 2001
From: Abhimithra Karthikeya <karthikeya.surabhi@gmail.com>
Date: Wed, 19 Dec 2018 15:53:43 +0530
Subject: [PATCH] Adding NonNull annotation (#6313)

---
 src/main/java/io/reactivex/Completable.java |  56 ++++++
 src/main/java/io/reactivex/Flowable.java    | 210 ++++++++++++++++++++
 src/main/java/io/reactivex/Maybe.java       | 101 ++++++++++
 src/main/java/io/reactivex/Observable.java  |  49 +++++
 src/main/java/io/reactivex/Single.java      |  87 ++++++++
 5 files changed, 503 insertions(+)

diff --git a/src/main/java/io/reactivex/Completable.java b/src/main/java/io/reactivex/Completable.java
index 948d8aecde..9d8325e3b6 100644
--- a/src/main/java/io/reactivex/Completable.java
+++ b/src/main/java/io/reactivex/Completable.java
@@ -118,6 +118,7 @@ public abstract class Completable implements CompletableSource {
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable ambArray(final CompletableSource... sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -146,6 +147,7 @@ public static Completable ambArray(final CompletableSource... sources) {
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable amb(final Iterable<? extends CompletableSource> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -164,6 +166,7 @@ public static Completable amb(final Iterable<? extends CompletableSource> source
      * @return a Completable instance that completes immediately
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable complete() {
         return RxJavaPlugins.onAssembly(CompletableEmpty.INSTANCE);
@@ -182,6 +185,7 @@ public static Completable complete() {
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable concatArray(CompletableSource... sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -207,6 +211,7 @@ public static Completable concatArray(CompletableSource... sources) {
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable concat(Iterable<? extends CompletableSource> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -253,6 +258,7 @@ public static Completable concat(Publisher<? extends CompletableSource> sources)
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.FULL)
     public static Completable concat(Publisher<? extends CompletableSource> sources, int prefetch) {
@@ -297,6 +303,7 @@ public static Completable concat(Publisher<? extends CompletableSource> sources,
      * @see Cancellable
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable create(CompletableOnSubscribe source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -319,6 +326,7 @@ public static Completable create(CompletableOnSubscribe source) {
      * @throws NullPointerException if source is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable unsafeCreate(CompletableSource source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -340,6 +348,7 @@ public static Completable unsafeCreate(CompletableSource source) {
      * @return the Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable defer(final Callable<? extends CompletableSource> completableSupplier) {
         ObjectHelper.requireNonNull(completableSupplier, "completableSupplier");
@@ -363,6 +372,7 @@ public static Completable defer(final Callable<? extends CompletableSource> comp
      * @throws NullPointerException if errorSupplier is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable error(final Callable<? extends Throwable> errorSupplier) {
         ObjectHelper.requireNonNull(errorSupplier, "errorSupplier is null");
@@ -382,6 +392,7 @@ public static Completable error(final Callable<? extends Throwable> errorSupplie
      * @throws NullPointerException if error is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable error(final Throwable error) {
         ObjectHelper.requireNonNull(error, "error is null");
@@ -409,6 +420,7 @@ public static Completable error(final Throwable error) {
      * @throws NullPointerException if run is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable fromAction(final Action run) {
         ObjectHelper.requireNonNull(run, "run is null");
@@ -435,6 +447,7 @@ public static Completable fromAction(final Action run) {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable fromCallable(final Callable<?> callable) {
         ObjectHelper.requireNonNull(callable, "callable is null");
@@ -455,6 +468,7 @@ public static Completable fromCallable(final Callable<?> callable) {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable fromFuture(final Future<?> future) {
         ObjectHelper.requireNonNull(future, "future is null");
@@ -479,6 +493,7 @@ public static Completable fromFuture(final Future<?> future) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Completable fromMaybe(final MaybeSource<T> maybe) {
         ObjectHelper.requireNonNull(maybe, "maybe is null");
@@ -499,6 +514,7 @@ public static <T> Completable fromMaybe(final MaybeSource<T> maybe) {
      * @throws NullPointerException if run is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable fromRunnable(final Runnable run) {
         ObjectHelper.requireNonNull(run, "run is null");
@@ -520,6 +536,7 @@ public static Completable fromRunnable(final Runnable run) {
      * @throws NullPointerException if flowable is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Completable fromObservable(final ObservableSource<T> observable) {
         ObjectHelper.requireNonNull(observable, "observable is null");
@@ -556,6 +573,7 @@ public static <T> Completable fromObservable(final ObservableSource<T> observabl
      * @see #create(CompletableOnSubscribe)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Completable fromPublisher(final Publisher<T> publisher) {
@@ -578,6 +596,7 @@ public static <T> Completable fromPublisher(final Publisher<T> publisher) {
      * @throws NullPointerException if single is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Completable fromSingle(final SingleSource<T> single) {
         ObjectHelper.requireNonNull(single, "single is null");
@@ -612,6 +631,7 @@ public static <T> Completable fromSingle(final SingleSource<T> single) {
      * @see #mergeArrayDelayError(CompletableSource...)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable mergeArray(CompletableSource... sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -652,6 +672,7 @@ public static Completable mergeArray(CompletableSource... sources) {
      * @see #mergeDelayError(Iterable)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable merge(Iterable<? extends CompletableSource> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -753,6 +774,7 @@ public static Completable merge(Publisher<? extends CompletableSource> sources,
      * @throws IllegalArgumentException if maxConcurrency is less than 1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.FULL)
     private static Completable merge0(Publisher<? extends CompletableSource> sources, int maxConcurrency, boolean delayErrors) {
@@ -776,6 +798,7 @@ private static Completable merge0(Publisher<? extends CompletableSource> sources
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable mergeArrayDelayError(CompletableSource... sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -797,6 +820,7 @@ public static Completable mergeArrayDelayError(CompletableSource... sources) {
      * @throws NullPointerException if sources is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable mergeDelayError(Iterable<? extends CompletableSource> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -902,6 +926,7 @@ public static Completable timer(long delay, TimeUnit unit) {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Completable timer(final long delay, final TimeUnit unit, final Scheduler scheduler) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -968,6 +993,7 @@ public static <R> Completable using(Callable<R> resourceSupplier,
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <R> Completable using(
             final Callable<R> resourceSupplier,
@@ -995,6 +1021,7 @@ public static <R> Completable using(
      * @throws NullPointerException if source is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static Completable wrap(CompletableSource source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -1019,6 +1046,7 @@ public static Completable wrap(CompletableSource source) {
      * @throws NullPointerException if other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable ambWith(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -1042,6 +1070,7 @@ public final Completable ambWith(CompletableSource other) {
      * @throws NullPointerException if next is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Observable<T> andThen(ObservableSource<T> next) {
         ObjectHelper.requireNonNull(next, "next is null");
@@ -1068,6 +1097,7 @@ public final <T> Observable<T> andThen(ObservableSource<T> next) {
      * @throws NullPointerException if next is null
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Flowable<T> andThen(Publisher<T> next) {
@@ -1092,6 +1122,7 @@ public final <T> Flowable<T> andThen(Publisher<T> next) {
      * @return Single that composes this Completable and next
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Single<T> andThen(SingleSource<T> next) {
         ObjectHelper.requireNonNull(next, "next is null");
@@ -1115,6 +1146,7 @@ public final <T> Single<T> andThen(SingleSource<T> next) {
      * @return Maybe that composes this Completable and next
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Maybe<T> andThen(MaybeSource<T> next) {
         ObjectHelper.requireNonNull(next, "next is null");
@@ -1207,6 +1239,7 @@ public final void blockingAwait() {
      * @throws RuntimeException wrapping an InterruptedException if the current thread is interrupted
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final boolean blockingAwait(long timeout, TimeUnit unit) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -1320,6 +1353,7 @@ public final Completable compose(CompletableTransformer transformer) {
      * @see #andThen(Publisher)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable concatWith(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -1383,6 +1417,7 @@ public final Completable delay(long delay, TimeUnit unit, Scheduler scheduler) {
      * @throws NullPointerException if unit or scheduler is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Completable delay(final long delay, final TimeUnit unit, final Scheduler scheduler, final boolean delayError) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -1514,6 +1549,7 @@ public final Completable doOnError(Consumer<? super Throwable> onError) {
      * @throws NullPointerException if onEvent is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable doOnEvent(final Consumer<? super Throwable> onEvent) {
         ObjectHelper.requireNonNull(onEvent, "onEvent is null");
@@ -1535,6 +1571,7 @@ public final Completable doOnEvent(final Consumer<? super Throwable> onEvent) {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     private Completable doOnLifecycle(
             final Consumer<? super Disposable> onSubscribe,
@@ -1639,6 +1676,7 @@ public final Completable doAfterTerminate(final Action onAfterTerminate) {
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable doFinally(Action onFinally) {
         ObjectHelper.requireNonNull(onFinally, "onFinally is null");
@@ -1776,6 +1814,7 @@ public final Completable doFinally(Action onFinally) {
      * @see #compose(CompletableTransformer)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable lift(final CompletableOperator onLift) {
         ObjectHelper.requireNonNull(onLift, "onLift is null");
@@ -1817,6 +1856,7 @@ public final <T> Single<Notification<T>> materialize() {
      * @throws NullPointerException if other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable mergeWith(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -1836,6 +1876,7 @@ public final Completable mergeWith(CompletableSource other) {
      * @throws NullPointerException if scheduler is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Completable observeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -1873,6 +1914,7 @@ public final Completable onErrorComplete() {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable onErrorComplete(final Predicate<? super Throwable> predicate) {
         ObjectHelper.requireNonNull(predicate, "predicate is null");
@@ -1895,6 +1937,7 @@ public final Completable onErrorComplete(final Predicate<? super Throwable> pred
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable onErrorResumeNext(final Function<? super Throwable, ? extends CompletableSource> errorMapper) {
         ObjectHelper.requireNonNull(errorMapper, "errorMapper is null");
@@ -2153,6 +2196,7 @@ public final Completable retryWhen(Function<? super Flowable<Throwable>, ? exten
      * @throws NullPointerException if other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable startWith(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2174,6 +2218,7 @@ public final Completable startWith(CompletableSource other) {
      * @throws NullPointerException if other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Observable<T> startWith(Observable<T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2197,6 +2242,7 @@ public final <T> Observable<T> startWith(Observable<T> other) {
      * @throws NullPointerException if other is null
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Flowable<T> startWith(Publisher<T> other) {
@@ -2319,6 +2365,7 @@ public final <E extends CompletableObserver> E subscribeWith(E observer) {
      * @throws NullPointerException if either callback is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Action onComplete, final Consumer<? super Throwable> onError) {
         ObjectHelper.requireNonNull(onError, "onError is null");
@@ -2346,6 +2393,7 @@ public final Disposable subscribe(final Action onComplete, final Consumer<? supe
      * @return the Disposable that allows disposing the subscription
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Action onComplete) {
         ObjectHelper.requireNonNull(onComplete, "onComplete is null");
@@ -2369,6 +2417,7 @@ public final Disposable subscribe(final Action onComplete) {
      * @throws NullPointerException if scheduler is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Completable subscribeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -2395,6 +2444,7 @@ public final Completable subscribeOn(final Scheduler scheduler) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable takeUntil(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2439,6 +2489,7 @@ public final Completable timeout(long timeout, TimeUnit unit) {
      * @throws NullPointerException if unit or other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.COMPUTATION)
     public final Completable timeout(long timeout, TimeUnit unit, CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2486,6 +2537,7 @@ public final Completable timeout(long timeout, TimeUnit unit, Scheduler schedule
      * @throws NullPointerException if unit, scheduler or other is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Completable timeout(long timeout, TimeUnit unit, Scheduler scheduler, CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2509,6 +2561,7 @@ public final Completable timeout(long timeout, TimeUnit unit, Scheduler schedule
      * @throws NullPointerException if unit or scheduler
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     private Completable timeout0(long timeout, TimeUnit unit, Scheduler scheduler, CompletableSource other) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -2625,6 +2678,7 @@ public final <T> Observable<T> toObservable() {
      * @throws NullPointerException if completionValueSupplier is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Single<T> toSingle(final Callable<? extends T> completionValueSupplier) {
         ObjectHelper.requireNonNull(completionValueSupplier, "completionValueSupplier is null");
@@ -2646,6 +2700,7 @@ public final <T> Single<T> toSingle(final Callable<? extends T> completionValueS
      * @throws NullPointerException if completionValue is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T> Single<T> toSingleDefault(final T completionValue) {
         ObjectHelper.requireNonNull(completionValue, "completionValue is null");
@@ -2666,6 +2721,7 @@ public final <T> Single<T> toSingleDefault(final T completionValue) {
      * @throws NullPointerException if scheduler is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Completable unsubscribeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
diff --git a/src/main/java/io/reactivex/Flowable.java b/src/main/java/io/reactivex/Flowable.java
index 77964b0fad..0b33a191a2 100644
--- a/src/main/java/io/reactivex/Flowable.java
+++ b/src/main/java/io/reactivex/Flowable.java
@@ -87,6 +87,7 @@ public abstract class Flowable<T> implements Publisher<T> {
      * @see <a href="http://reactivex.io/documentation/operators/amb.html">ReactiveX operators documentation: Amb</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> amb(Iterable<? extends Publisher<? extends T>> sources) {
@@ -116,6 +117,7 @@ public static <T> Flowable<T> amb(Iterable<? extends Publisher<? extends T>> sou
      * @see <a href="http://reactivex.io/documentation/operators/amb.html">ReactiveX operators documentation: Amb</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> ambArray(Publisher<? extends T>... sources) {
@@ -269,6 +271,7 @@ public static <T, R> Flowable<R> combineLatest(Function<? super Object[], ? exte
      */
     @SchedulerSupport(SchedulerSupport.NONE)
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     public static <T, R> Flowable<R> combineLatest(Publisher<? extends T>[] sources, Function<? super Object[], ? extends R> combiner, int bufferSize) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -366,6 +369,7 @@ public static <T, R> Flowable<R> combineLatest(Iterable<? extends Publisher<? ex
      */
     @SchedulerSupport(SchedulerSupport.NONE)
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     public static <T, R> Flowable<R> combineLatest(Iterable<? extends Publisher<? extends T>> sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -556,6 +560,7 @@ public static <T, R> Flowable<R> combineLatestDelayError(Function<? super Object
      */
     @SchedulerSupport(SchedulerSupport.NONE)
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     public static <T, R> Flowable<R> combineLatestDelayError(Publisher<? extends T>[] sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -747,6 +752,7 @@ public static <T1, T2, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, R> Flowable<R> combineLatest(
@@ -799,6 +805,7 @@ public static <T1, T2, T3, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, R> Flowable<R> combineLatest(
@@ -855,6 +862,7 @@ public static <T1, T2, T3, T4, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, R> Flowable<R> combineLatest(
@@ -916,6 +924,7 @@ public static <T1, T2, T3, T4, T5, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, R> Flowable<R> combineLatest(
@@ -981,6 +990,7 @@ public static <T1, T2, T3, T4, T5, T6, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, R> Flowable<R> combineLatest(
@@ -1051,6 +1061,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Flowable<R> combineLatest(
@@ -1125,6 +1136,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Flowable<R> combineLatest(
@@ -1166,6 +1178,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Flowable<R> combineLatest(
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(Iterable<? extends Publisher<? extends T>> sources) {
@@ -1261,6 +1274,7 @@ public static <T> Flowable<T> concat(Publisher<? extends Publisher<? extends T>>
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(Publisher<? extends T> source1, Publisher<? extends T> source2) {
@@ -1297,6 +1311,7 @@ public static <T> Flowable<T> concat(Publisher<? extends T> source1, Publisher<?
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(
@@ -1338,6 +1353,7 @@ public static <T> Flowable<T> concat(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(
@@ -1470,6 +1486,7 @@ public static <T> Flowable<T> concatArrayEager(Publisher<? extends T>... sources
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "rawtypes", "unchecked" })
@@ -1564,6 +1581,7 @@ public static <T> Flowable<T> concatArrayEagerDelayError(int maxConcurrency, int
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concatDelayError(Iterable<? extends Publisher<? extends T>> sources) {
@@ -1668,6 +1686,7 @@ public static <T> Flowable<T> concatEager(Publisher<? extends Publisher<? extend
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "rawtypes", "unchecked" })
@@ -1727,6 +1746,7 @@ public static <T> Flowable<T> concatEager(Iterable<? extends Publisher<? extends
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "rawtypes", "unchecked" })
@@ -1784,6 +1804,7 @@ public static <T> Flowable<T> concatEager(Iterable<? extends Publisher<? extends
      * @see Cancellable
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> create(FlowableOnSubscribe<T> source, BackpressureStrategy mode) {
@@ -1820,6 +1841,7 @@ public static <T> Flowable<T> create(FlowableOnSubscribe<T> source, Backpressure
      * @see <a href="http://reactivex.io/documentation/operators/defer.html">ReactiveX operators documentation: Defer</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> defer(Callable<? extends Publisher<? extends T>> supplier) {
@@ -1874,6 +1896,7 @@ public static <T> Flowable<T> empty() {
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> error(Callable<? extends Throwable> supplier) {
@@ -1902,6 +1925,7 @@ public static <T> Flowable<T> error(Callable<? extends Throwable> supplier) {
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> error(final Throwable throwable) {
@@ -1929,6 +1953,7 @@ public static <T> Flowable<T> error(final Throwable throwable) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> fromArray(T... items) {
@@ -1974,6 +1999,7 @@ public static <T> Flowable<T> fromArray(T... items) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> fromCallable(Callable<? extends T> supplier) {
@@ -2010,6 +2036,7 @@ public static <T> Flowable<T> fromCallable(Callable<? extends T> supplier) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> fromFuture(Future<? extends T> future) {
@@ -2050,6 +2077,7 @@ public static <T> Flowable<T> fromFuture(Future<? extends T> future) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> fromFuture(Future<? extends T> future, long timeout, TimeUnit unit) {
@@ -2095,6 +2123,7 @@ public static <T> Flowable<T> fromFuture(Future<? extends T> future, long timeou
      */
     @SuppressWarnings({ "unchecked", "cast" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static <T> Flowable<T> fromFuture(Future<? extends T> future, long timeout, TimeUnit unit, Scheduler scheduler) {
@@ -2133,6 +2162,7 @@ public static <T> Flowable<T> fromFuture(Future<? extends T> future, long timeou
      */
     @SuppressWarnings({ "cast", "unchecked" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static <T> Flowable<T> fromFuture(Future<? extends T> future, Scheduler scheduler) {
@@ -2161,6 +2191,7 @@ public static <T> Flowable<T> fromFuture(Future<? extends T> future, Scheduler s
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> fromIterable(Iterable<? extends T> source) {
@@ -2196,6 +2227,7 @@ public static <T> Flowable<T> fromIterable(Iterable<? extends T> source) {
      * @see #create(FlowableOnSubscribe, BackpressureStrategy)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -2230,6 +2262,7 @@ public static <T> Flowable<T> fromPublisher(final Publisher<? extends T> source)
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> generate(final Consumer<Emitter<T>> generator) {
@@ -2263,6 +2296,7 @@ public static <T> Flowable<T> generate(final Consumer<Emitter<T>> generator) {
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Flowable<T> generate(Callable<S> initialState, final BiConsumer<S, Emitter<T>> generator) {
@@ -2297,6 +2331,7 @@ public static <T, S> Flowable<T> generate(Callable<S> initialState, final BiCons
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Flowable<T> generate(Callable<S> initialState, final BiConsumer<S, Emitter<T>> generator,
@@ -2363,6 +2398,7 @@ public static <T, S> Flowable<T> generate(Callable<S> initialState, BiFunction<S
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Flowable<T> generate(Callable<S> initialState, BiFunction<S, Emitter<T>, S> generator, Consumer<? super S> disposeState) {
@@ -2432,6 +2468,7 @@ public static Flowable<Long> interval(long initialDelay, long period, TimeUnit u
      * @since 1.0.12
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Flowable<Long> interval(long initialDelay, long period, TimeUnit unit, Scheduler scheduler) {
@@ -2539,6 +2576,7 @@ public static Flowable<Long> intervalRange(long start, long count, long initialD
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Flowable<Long> intervalRange(long start, long count, long initialDelay, long period, TimeUnit unit, Scheduler scheduler) {
@@ -2590,6 +2628,7 @@ public static Flowable<Long> intervalRange(long start, long count, long initialD
      * @see #fromIterable(Iterable)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item) {
@@ -2619,6 +2658,7 @@ public static <T> Flowable<T> just(T item) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2) {
@@ -2652,6 +2692,7 @@ public static <T> Flowable<T> just(T item1, T item2) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3) {
@@ -2688,6 +2729,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4) {
@@ -2727,6 +2769,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5) {
@@ -2769,6 +2812,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5)
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5, T item6) {
@@ -2814,6 +2858,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5,
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7) {
@@ -2862,6 +2907,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5,
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8) {
@@ -2913,6 +2959,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5,
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8, T item9) {
@@ -2967,6 +3014,7 @@ public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5,
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8, T item9, T item10) {
@@ -3357,6 +3405,7 @@ public static <T> Flowable<T> mergeArray(Publisher<? extends T>... sources) {
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> merge(Publisher<? extends T> source1, Publisher<? extends T> source2) {
@@ -3406,6 +3455,7 @@ public static <T> Flowable<T> merge(Publisher<? extends T> source1, Publisher<?
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> merge(Publisher<? extends T> source1, Publisher<? extends T> source2, Publisher<? extends T> source3) {
@@ -3458,6 +3508,7 @@ public static <T> Flowable<T> merge(Publisher<? extends T> source1, Publisher<?
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> merge(
@@ -3767,6 +3818,7 @@ public static <T> Flowable<T> mergeArrayDelayError(Publisher<? extends T>... sou
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(Publisher<? extends T> source1, Publisher<? extends T> source2) {
@@ -3809,6 +3861,7 @@ public static <T> Flowable<T> mergeDelayError(Publisher<? extends T> source1, Pu
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(Publisher<? extends T> source1, Publisher<? extends T> source2, Publisher<? extends T> source3) {
@@ -3854,6 +3907,7 @@ public static <T> Flowable<T> mergeDelayError(Publisher<? extends T> source1, Pu
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(
@@ -4069,6 +4123,7 @@ public static <T> Single<Boolean> sequenceEqual(Publisher<? extends T> source1,
      * @see <a href="http://reactivex.io/documentation/operators/sequenceequal.html">ReactiveX operators documentation: SequenceEqual</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<Boolean> sequenceEqual(Publisher<? extends T> source1, Publisher<? extends T> source2,
@@ -4319,6 +4374,7 @@ public static Flowable<Long> timer(long delay, TimeUnit unit) {
      * @see <a href="http://reactivex.io/documentation/operators/timer.html">ReactiveX operators documentation: Timer</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Flowable<Long> timer(long delay, TimeUnit unit, Scheduler scheduler) {
@@ -4347,6 +4403,7 @@ public static Flowable<Long> timer(long delay, TimeUnit unit, Scheduler schedule
      * instead.
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.NONE)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> unsafeCreate(Publisher<T> onSubscribe) {
@@ -4420,6 +4477,7 @@ public static <T, D> Flowable<T> using(Callable<? extends D> resourceSupplier,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, D> Flowable<T> using(Callable<? extends D> resourceSupplier,
@@ -4476,6 +4534,7 @@ public static <T, D> Flowable<T> using(Callable<? extends D> resourceSupplier,
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Flowable<R> zip(Iterable<? extends Publisher<? extends T>> sources, Function<? super Object[], ? extends R> zipper) {
@@ -4530,6 +4589,7 @@ public static <T, R> Flowable<R> zip(Iterable<? extends Publisher<? extends T>>
      */
     @SuppressWarnings({ "rawtypes", "unchecked", "cast" })
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Flowable<R> zip(Publisher<? extends Publisher<? extends T>> sources,
@@ -4588,6 +4648,7 @@ public static <T, R> Flowable<R> zip(Publisher<? extends Publisher<? extends T>>
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, R> Flowable<R> zip(
@@ -4649,6 +4710,7 @@ public static <T1, T2, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, R> Flowable<R> zip(
@@ -4711,6 +4773,7 @@ public static <T1, T2, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, R> Flowable<R> zip(
@@ -4775,6 +4838,7 @@ public static <T1, T2, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, R> Flowable<R> zip(
@@ -4843,6 +4907,7 @@ public static <T1, T2, T3, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, R> Flowable<R> zip(
@@ -4916,6 +4981,7 @@ public static <T1, T2, T3, T4, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, R> Flowable<R> zip(
@@ -4992,6 +5058,7 @@ public static <T1, T2, T3, T4, T5, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, R> Flowable<R> zip(
@@ -5072,6 +5139,7 @@ public static <T1, T2, T3, T4, T5, T6, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, R> Flowable<R> zip(
@@ -5157,6 +5225,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Flowable<R> zip(
@@ -5246,6 +5315,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Flowable<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Flowable<R> zip(
@@ -5316,6 +5386,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Flowable<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Flowable<R> zipArray(Function<? super Object[], ? extends R> zipper,
@@ -5378,6 +5449,7 @@ public static <T, R> Flowable<R> zipArray(Function<? super Object[], ? extends R
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Flowable<R> zipIterable(Iterable<? extends Publisher<? extends T>> sources,
@@ -5413,6 +5485,7 @@ public static <T, R> Flowable<R> zipIterable(Iterable<? extends Publisher<? exte
      * @see <a href="http://reactivex.io/documentation/operators/all.html">ReactiveX operators documentation: All</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<Boolean> all(Predicate<? super T> predicate) {
@@ -5442,6 +5515,7 @@ public final Single<Boolean> all(Predicate<? super T> predicate) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> ambWith(Publisher<? extends T> other) {
@@ -5473,6 +5547,7 @@ public final Flowable<T> ambWith(Publisher<? extends T> other) {
      * @see <a href="http://reactivex.io/documentation/operators/contains.html">ReactiveX operators documentation: Contains</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<Boolean> any(Predicate<? super T> predicate) {
@@ -6203,6 +6278,7 @@ public final Flowable<List<T>> buffer(int count, int skip) {
      * @see <a href="http://reactivex.io/documentation/operators/buffer.html">ReactiveX operators documentation: Buffer</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U extends Collection<? super T>> Flowable<U> buffer(int count, int skip, Callable<U> bufferSupplier) {
@@ -6352,6 +6428,7 @@ public final Flowable<List<T>> buffer(long timespan, long timeskip, TimeUnit uni
      * @see <a href="http://reactivex.io/documentation/operators/buffer.html">ReactiveX operators documentation: Buffer</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final <U extends Collection<? super T>> Flowable<U> buffer(long timespan, long timeskip, TimeUnit unit,
@@ -6965,6 +7042,7 @@ public final Flowable<T> cacheWithInitialCapacity(int initialCapacity) {
      * @see <a href="http://reactivex.io/documentation/operators/map.html">ReactiveX operators documentation: Map</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> cast(final Class<U> clazz) {
@@ -7002,6 +7080,7 @@ public final <U> Flowable<U> cast(final Class<U> clazz) {
      * @see <a href="http://reactivex.io/documentation/operators/reduce.html">ReactiveX operators documentation: Reduce</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<U> collect(Callable<? extends U> initialItemSupplier, BiConsumer<? super U, ? super T> collector) {
@@ -7040,6 +7119,7 @@ public final <U> Single<U> collect(Callable<? extends U> initialItemSupplier, Bi
      * @see <a href="http://reactivex.io/documentation/operators/reduce.html">ReactiveX operators documentation: Reduce</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<U> collectInto(final U initialItem, BiConsumer<? super U, ? super T> collector) {
@@ -7137,6 +7217,7 @@ public final <R> Flowable<R> concatMap(Function<? super T, ? extends Publisher<?
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMap(Function<? super T, ? extends Publisher<? extends R>> mapper, int prefetch) {
@@ -7205,6 +7286,7 @@ public final Completable concatMapCompletable(Function<? super T, ? extends Comp
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.FULL)
     public final Completable concatMapCompletable(Function<? super T, ? extends CompletableSource> mapper, int prefetch) {
@@ -7307,6 +7389,7 @@ public final Completable concatMapCompletableDelayError(Function<? super T, ? ex
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.FULL)
     public final Completable concatMapCompletableDelayError(Function<? super T, ? extends CompletableSource> mapper, boolean tillTheEnd, int prefetch) {
@@ -7370,6 +7453,7 @@ public final <R> Flowable<R> concatMapDelayError(Function<? super T, ? extends P
      * @return the new Publisher instance with the concatenation behavior
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapDelayError(Function<? super T, ? extends Publisher<? extends R>> mapper,
@@ -7437,6 +7521,7 @@ public final <R> Flowable<R> concatMapEager(Function<? super T, ? extends Publis
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapEager(Function<? super T, ? extends Publisher<? extends R>> mapper,
@@ -7506,6 +7591,7 @@ public final <R> Flowable<R> concatMapEagerDelayError(Function<? super T, ? exte
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapEagerDelayError(Function<? super T, ? extends Publisher<? extends R>> mapper,
@@ -7570,6 +7656,7 @@ public final <U> Flowable<U> concatMapIterable(Function<? super T, ? extends Ite
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> concatMapIterable(final Function<? super T, ? extends Iterable<? extends U>> mapper, int prefetch) {
@@ -7638,6 +7725,7 @@ public final <R> Flowable<R> concatMapMaybe(Function<? super T, ? extends MaybeS
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapMaybe(Function<? super T, ? extends MaybeSource<? extends R>> mapper, int prefetch) {
@@ -7748,6 +7836,7 @@ public final <R> Flowable<R> concatMapMaybeDelayError(Function<? super T, ? exte
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapMaybeDelayError(Function<? super T, ? extends MaybeSource<? extends R>> mapper, boolean tillTheEnd, int prefetch) {
@@ -7816,6 +7905,7 @@ public final <R> Flowable<R> concatMapSingle(Function<? super T, ? extends Singl
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapSingle(Function<? super T, ? extends SingleSource<? extends R>> mapper, int prefetch) {
@@ -7926,6 +8016,7 @@ public final <R> Flowable<R> concatMapSingleDelayError(Function<? super T, ? ext
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> concatMapSingleDelayError(Function<? super T, ? extends SingleSource<? extends R>> mapper, boolean tillTheEnd, int prefetch) {
@@ -7955,6 +8046,7 @@ public final <R> Flowable<R> concatMapSingleDelayError(Function<? super T, ? ext
      * @see <a href="http://reactivex.io/documentation/operators/concat.html">ReactiveX operators documentation: Concat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> concatWith(Publisher<? extends T> other) {
@@ -8059,6 +8151,7 @@ public final Flowable<T> concatWith(@NonNull CompletableSource other) {
      * @see <a href="http://reactivex.io/documentation/operators/contains.html">ReactiveX operators documentation: Contains</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<Boolean> contains(final Object item) {
@@ -8114,6 +8207,7 @@ public final Single<Long> count() {
      * @see <a href="https://github.com/ReactiveX/RxJava/wiki/Backpressure">RxJava wiki: Backpressure</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> debounce(Function<? super T, ? extends Publisher<U>> debounceIndicator) {
@@ -8187,6 +8281,7 @@ public final Flowable<T> debounce(long timeout, TimeUnit unit) {
      * @see #throttleWithTimeout(long, TimeUnit, Scheduler)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> debounce(long timeout, TimeUnit unit, Scheduler scheduler) {
@@ -8217,6 +8312,7 @@ public final Flowable<T> debounce(long timeout, TimeUnit unit, Scheduler schedul
      * @see <a href="http://reactivex.io/documentation/operators/defaultifempty.html">ReactiveX operators documentation: DefaultIfEmpty</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> defaultIfEmpty(T defaultItem) {
@@ -8252,6 +8348,7 @@ public final Flowable<T> defaultIfEmpty(T defaultItem) {
      * @see <a href="http://reactivex.io/documentation/operators/delay.html">ReactiveX operators documentation: Delay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> delay(final Function<? super T, ? extends Publisher<U>> itemDelayIndicator) {
@@ -8367,6 +8464,7 @@ public final Flowable<T> delay(long delay, TimeUnit unit, Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/delay.html">ReactiveX operators documentation: Delay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> delay(long delay, TimeUnit unit, Scheduler scheduler, boolean delayError) {
@@ -8435,6 +8533,7 @@ public final <U, V> Flowable<T> delay(Publisher<U> subscriptionIndicator,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> delaySubscription(Publisher<U> subscriptionIndicator) {
@@ -8598,6 +8697,7 @@ public final <T2> Flowable<T2> dematerialize() {
      */
     @Experimental
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     public final <R> Flowable<R> dematerialize(Function<? super T, Notification<R>> selector) {
@@ -9011,6 +9111,7 @@ public final Flowable<T> doOnComplete(Action onComplete) {
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     private Flowable<T> doOnEach(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
@@ -9040,6 +9141,7 @@ private Flowable<T> doOnEach(Consumer<? super T> onNext, Consumer<? super Throwa
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> doOnEach(final Consumer<? super Notification<T>> onNotification) {
@@ -9076,6 +9178,7 @@ public final Flowable<T> doOnEach(final Consumer<? super Notification<T>> onNoti
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> doOnEach(final Subscriber<? super T> subscriber) {
@@ -9138,6 +9241,7 @@ public final Flowable<T> doOnError(Consumer<? super Throwable> onError) {
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> doOnLifecycle(final Consumer<? super Subscription> onSubscribe,
@@ -9312,6 +9416,7 @@ public final Maybe<T> elementAt(long index) {
      * @see <a href="http://reactivex.io/documentation/operators/elementat.html">ReactiveX operators documentation: ElementAt</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> elementAt(long index, T defaultItem) {
@@ -9373,6 +9478,7 @@ public final Single<T> elementAtOrError(long index) {
      * @see <a href="http://reactivex.io/documentation/operators/filter.html">ReactiveX operators documentation: Filter</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> filter(Predicate<? super T> predicate) {
@@ -9629,6 +9735,7 @@ public final <R> Flowable<R> flatMap(Function<? super T, ? extends Publisher<? e
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMap(Function<? super T, ? extends Publisher<? extends R>> mapper,
@@ -9677,6 +9784,7 @@ public final <R> Flowable<R> flatMap(Function<? super T, ? extends Publisher<? e
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMap(
@@ -9723,6 +9831,7 @@ public final <R> Flowable<R> flatMap(
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMap(
@@ -9893,6 +10002,7 @@ public final <U, R> Flowable<R> flatMap(Function<? super T, ? extends Publisher<
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Flowable<R> flatMap(final Function<? super T, ? extends Publisher<? extends U>> mapper,
@@ -9981,6 +10091,7 @@ public final Completable flatMapCompletable(Function<? super T, ? extends Comple
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable flatMapCompletable(Function<? super T, ? extends CompletableSource> mapper, boolean delayErrors, int maxConcurrency) {
@@ -10045,6 +10156,7 @@ public final <U> Flowable<U> flatMapIterable(final Function<? super T, ? extends
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flatMapIterable(final Function<? super T, ? extends Iterable<? extends U>> mapper, int bufferSize) {
@@ -10081,6 +10193,7 @@ public final <U> Flowable<U> flatMapIterable(final Function<? super T, ? extends
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, V> Flowable<V> flatMapIterable(final Function<? super T, ? extends Iterable<? extends U>> mapper,
@@ -10123,6 +10236,7 @@ public final <U, V> Flowable<V> flatMapIterable(final Function<? super T, ? exte
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, V> Flowable<V> flatMapIterable(final Function<? super T, ? extends Iterable<? extends U>> mapper,
@@ -10172,6 +10286,7 @@ public final <R> Flowable<R> flatMapMaybe(Function<? super T, ? extends MaybeSou
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMapMaybe(Function<? super T, ? extends MaybeSource<? extends R>> mapper, boolean delayErrors, int maxConcurrency) {
@@ -10220,6 +10335,7 @@ public final <R> Flowable<R> flatMapSingle(Function<? super T, ? extends SingleS
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMapSingle(Function<? super T, ? extends SingleSource<? extends R>> mapper, boolean delayErrors, int maxConcurrency) {
@@ -10340,6 +10456,7 @@ public final Disposable forEachWhile(Predicate<? super T> onNext, Consumer<? sup
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.NONE)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable forEachWhile(final Predicate<? super T> onNext, final Consumer<? super Throwable> onError,
@@ -10611,6 +10728,7 @@ public final <K, V> Flowable<GroupedFlowable<K, V>> groupBy(Function<? super T,
      * @see <a href="http://reactivex.io/documentation/operators/groupby.html">ReactiveX operators documentation: GroupBy</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K, V> Flowable<GroupedFlowable<K, V>> groupBy(Function<? super T, ? extends K> keySelector,
@@ -10723,6 +10841,7 @@ public final <K, V> Flowable<GroupedFlowable<K, V>> groupBy(Function<? super T,
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K, V> Flowable<GroupedFlowable<K, V>> groupBy(Function<? super T, ? extends K> keySelector,
@@ -10772,6 +10891,7 @@ public final <K, V> Flowable<GroupedFlowable<K, V>> groupBy(Function<? super T,
      * @see <a href="http://reactivex.io/documentation/operators/join.html">ReactiveX operators documentation: Join</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <TRight, TLeftEnd, TRightEnd, R> Flowable<R> groupJoin(
@@ -10893,6 +11013,7 @@ public final Single<Boolean> isEmpty() {
      * @see <a href="http://reactivex.io/documentation/operators/join.html">ReactiveX operators documentation: Join</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <TRight, TLeftEnd, TRightEnd, R> Flowable<R> join(
@@ -10950,6 +11071,7 @@ public final Maybe<T> lastElement() {
      * @see <a href="http://reactivex.io/documentation/operators/last.html">ReactiveX operators documentation: Last</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> last(T defaultItem) {
@@ -11127,6 +11249,7 @@ public final Single<T> lastOrError() {
      * @see #compose(FlowableTransformer)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> lift(FlowableOperator<? extends R, ? super T> lifter) {
@@ -11201,6 +11324,7 @@ public final Flowable<T> limit(long count) {
      * @see <a href="http://reactivex.io/documentation/operators/map.html">ReactiveX operators documentation: Map</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> map(Function<? super T, ? extends R> mapper) {
@@ -11254,6 +11378,7 @@ public final Flowable<Notification<T>> materialize() {
      * @see <a href="http://reactivex.io/documentation/operators/merge.html">ReactiveX operators documentation: Merge</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> mergeWith(Publisher<? extends T> other) {
@@ -11281,6 +11406,7 @@ public final Flowable<T> mergeWith(Publisher<? extends T> other) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> mergeWith(@NonNull SingleSource<? extends T> other) {
@@ -11309,6 +11435,7 @@ public final Flowable<T> mergeWith(@NonNull SingleSource<? extends T> other) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> mergeWith(@NonNull MaybeSource<? extends T> other) {
@@ -11334,6 +11461,7 @@ public final Flowable<T> mergeWith(@NonNull MaybeSource<? extends T> other) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> mergeWith(@NonNull CompletableSource other) {
@@ -11446,6 +11574,7 @@ public final Flowable<T> observeOn(Scheduler scheduler, boolean delayError) {
      * @see #observeOn(Scheduler, boolean)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> observeOn(Scheduler scheduler, boolean delayError, int bufferSize) {
@@ -11473,6 +11602,7 @@ public final Flowable<T> observeOn(Scheduler scheduler, boolean delayError, int
      * @see <a href="http://reactivex.io/documentation/operators/filter.html">ReactiveX operators documentation: Filter</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> ofType(final Class<U> clazz) {
@@ -11649,6 +11779,7 @@ public final Flowable<T> onBackpressureBuffer(int capacity, boolean delayError,
      * @since 1.1.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onBackpressureBuffer(int capacity, boolean delayError, boolean unbounded,
@@ -11720,6 +11851,7 @@ public final Flowable<T> onBackpressureBuffer(int capacity, Action onOverflow) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onBackpressureBuffer(long capacity, Action onOverflow, BackpressureOverflowStrategy overflowStrategy) {
@@ -11776,6 +11908,7 @@ public final Flowable<T> onBackpressureDrop() {
      * @since 1.1.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onBackpressureDrop(Consumer<? super T> onDrop) {
@@ -11851,6 +11984,7 @@ public final Flowable<T> onBackpressureLatest() {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onErrorResumeNext(Function<? super Throwable, ? extends Publisher<? extends T>> resumeFunction) {
@@ -11894,6 +12028,7 @@ public final Flowable<T> onErrorResumeNext(Function<? super Throwable, ? extends
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onErrorResumeNext(final Publisher<? extends T> next) {
@@ -11933,6 +12068,7 @@ public final Flowable<T> onErrorResumeNext(final Publisher<? extends T> next) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onErrorReturn(Function<? super Throwable, ? extends T> valueSupplier) {
@@ -11972,6 +12108,7 @@ public final Flowable<T> onErrorReturn(Function<? super Throwable, ? extends T>
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onErrorReturnItem(final T item) {
@@ -12018,6 +12155,7 @@ public final Flowable<T> onErrorReturnItem(final T item) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> onExceptionResumeNext(final Publisher<? extends T> next) {
@@ -12226,6 +12364,7 @@ public final <R> Flowable<R> publish(Function<? super Flowable<T>, ? extends Pub
      * @see <a href="http://reactivex.io/documentation/operators/publish.html">ReactiveX operators documentation: Publish</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> publish(Function<? super Flowable<T>, ? extends Publisher<? extends R>> selector, int prefetch) {
@@ -12320,6 +12459,7 @@ public final Flowable<T> rebatchRequests(int n) {
      * @see <a href="http://en.wikipedia.org/wiki/Fold_(higher-order_function)">Wikipedia: Fold (higher-order function)</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> reduce(BiFunction<T, T, T> reducer) {
@@ -12381,6 +12521,7 @@ public final Maybe<T> reduce(BiFunction<T, T, T> reducer) {
      * @see #reduceWith(Callable, BiFunction)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> reduce(R seed, BiFunction<R, ? super T, R> reducer) {
@@ -12425,6 +12566,7 @@ public final <R> Single<R> reduce(R seed, BiFunction<R, ? super T, R> reducer) {
      * @see <a href="http://en.wikipedia.org/wiki/Fold_(higher-order_function)">Wikipedia: Fold (higher-order function)</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> reduceWith(Callable<R> seedSupplier, BiFunction<R, ? super T, R> reducer) {
@@ -12512,6 +12654,7 @@ public final Flowable<T> repeat(long times) {
      * @see <a href="http://reactivex.io/documentation/operators/repeat.html">ReactiveX operators documentation: Repeat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> repeatUntil(BooleanSupplier stop) {
@@ -12542,6 +12685,7 @@ public final Flowable<T> repeatUntil(BooleanSupplier stop) {
      * @see <a href="http://reactivex.io/documentation/operators/repeat.html">ReactiveX operators documentation: Repeat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> repeatWhen(final Function<? super Flowable<Object>, ? extends Publisher<?>> handler) {
@@ -12600,6 +12744,7 @@ public final ConnectableFlowable<T> replay() {
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publisher<R>> selector) {
@@ -12638,6 +12783,7 @@ public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publisher<R>> selector, final int bufferSize) {
@@ -12728,6 +12874,7 @@ public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publisher<R>> selector, final int bufferSize, final long time, final TimeUnit unit, final Scheduler scheduler) {
@@ -12772,6 +12919,7 @@ public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final <R> Flowable<R> replay(final Function<? super Flowable<T>, ? extends Publisher<R>> selector, final int bufferSize, final Scheduler scheduler) {
@@ -12851,6 +12999,7 @@ public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publisher<R>> selector, final long time, final TimeUnit unit, final Scheduler scheduler) {
@@ -12887,6 +13036,7 @@ public final <R> Flowable<R> replay(Function<? super Flowable<T>, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/replay.html">ReactiveX operators documentation: Replay</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final <R> Flowable<R> replay(final Function<? super Flowable<T>, ? extends Publisher<R>> selector, final Scheduler scheduler) {
@@ -13195,6 +13345,7 @@ public final Flowable<T> retry() {
      * @see <a href="http://reactivex.io/documentation/operators/retry.html">ReactiveX operators documentation: Retry</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> retry(BiPredicate<? super Integer, ? super Throwable> predicate) {
@@ -13252,6 +13403,7 @@ public final Flowable<T> retry(long count) {
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> retry(long times, Predicate<? super Throwable> predicate) {
@@ -13296,6 +13448,7 @@ public final Flowable<T> retry(Predicate<? super Throwable> predicate) {
      * @return the new Flowable instance
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> retryUntil(final BooleanSupplier stop) {
@@ -13381,6 +13534,7 @@ public final Flowable<T> retryUntil(final BooleanSupplier stop) {
      * @see <a href="http://reactivex.io/documentation/operators/retry.html">ReactiveX operators documentation: Retry</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> retryWhen(
@@ -13504,6 +13658,7 @@ public final Flowable<T> sample(long period, TimeUnit unit, boolean emitLast) {
      * @see #throttleLast(long, TimeUnit, Scheduler)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> sample(long period, TimeUnit unit, Scheduler scheduler) {
@@ -13544,6 +13699,7 @@ public final Flowable<T> sample(long period, TimeUnit unit, Scheduler scheduler)
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> sample(long period, TimeUnit unit, Scheduler scheduler, boolean emitLast) {
@@ -13575,6 +13731,7 @@ public final Flowable<T> sample(long period, TimeUnit unit, Scheduler scheduler,
      * @see <a href="https://github.com/ReactiveX/RxJava/wiki/Backpressure">RxJava wiki: Backpressure</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> sample(Publisher<U> sampler) {
@@ -13612,6 +13769,7 @@ public final <U> Flowable<T> sample(Publisher<U> sampler) {
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> sample(Publisher<U> sampler, boolean emitLast) {
@@ -13644,6 +13802,7 @@ public final <U> Flowable<T> sample(Publisher<U> sampler, boolean emitLast) {
      * @see <a href="http://reactivex.io/documentation/operators/scan.html">ReactiveX operators documentation: Scan</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> scan(BiFunction<T, T, T> accumulator) {
@@ -13697,6 +13856,7 @@ public final Flowable<T> scan(BiFunction<T, T, T> accumulator) {
      * @see <a href="http://reactivex.io/documentation/operators/scan.html">ReactiveX operators documentation: Scan</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> scan(final R initialValue, BiFunction<R, ? super T, R> accumulator) {
@@ -13736,6 +13896,7 @@ public final <R> Flowable<R> scan(final R initialValue, BiFunction<R, ? super T,
      * @see <a href="http://reactivex.io/documentation/operators/scan.html">ReactiveX operators documentation: Scan</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> scanWith(Callable<R> seedSupplier, BiFunction<R, ? super T, R> accumulator) {
@@ -13847,6 +14008,7 @@ public final Maybe<T> singleElement() {
      * @see <a href="http://reactivex.io/documentation/operators/first.html">ReactiveX operators documentation: First</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> single(T defaultItem) {
@@ -14168,6 +14330,7 @@ public final Flowable<T> skipLast(long time, TimeUnit unit, Scheduler scheduler,
      * @see <a href="http://reactivex.io/documentation/operators/skiplast.html">ReactiveX operators documentation: SkipLast</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> skipLast(long time, TimeUnit unit, Scheduler scheduler, boolean delayError, int bufferSize) {
@@ -14201,6 +14364,7 @@ public final Flowable<T> skipLast(long time, TimeUnit unit, Scheduler scheduler,
      * @see <a href="http://reactivex.io/documentation/operators/skipuntil.html">ReactiveX operators documentation: SkipUntil</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> skipUntil(Publisher<U> other) {
@@ -14228,6 +14392,7 @@ public final <U> Flowable<T> skipUntil(Publisher<U> other) {
      * @see <a href="http://reactivex.io/documentation/operators/skipwhile.html">ReactiveX operators documentation: SkipWhile</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> skipWhile(Predicate<? super T> predicate) {
@@ -14283,6 +14448,7 @@ public final Flowable<T> sorted() {
      * @return a Flowable that emits the items emitted by the source Publisher in sorted order
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> sorted(Comparator<? super T> sortFunction) {
@@ -14340,6 +14506,7 @@ public final Flowable<T> startWith(Iterable<? extends T> items) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> startWith(Publisher<? extends T> other) {
@@ -14369,6 +14536,7 @@ public final Flowable<T> startWith(Publisher<? extends T> other) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> startWith(T value) {
@@ -14559,6 +14727,7 @@ public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super T
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
@@ -14719,6 +14888,7 @@ public final <E extends Subscriber<? super T>> E subscribeWith(E subscriber) {
      * @see #subscribeOn(Scheduler, boolean)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> subscribeOn(@NonNull Scheduler scheduler) {
@@ -14756,6 +14926,7 @@ public final Flowable<T> subscribeOn(@NonNull Scheduler scheduler) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> subscribeOn(@NonNull Scheduler scheduler, boolean requestOn) {
@@ -14786,6 +14957,7 @@ public final Flowable<T> subscribeOn(@NonNull Scheduler scheduler, boolean reque
      * @since 1.1.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> switchIfEmpty(Publisher<? extends T> other) {
@@ -14899,6 +15071,7 @@ public final <R> Flowable<R> switchMap(Function<? super T, ? extends Publisher<?
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable switchMapCompletable(@NonNull Function<? super T, ? extends CompletableSource> mapper) {
@@ -14945,6 +15118,7 @@ public final Completable switchMapCompletable(@NonNull Function<? super T, ? ext
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable switchMapCompletableDelayError(@NonNull Function<? super T, ? extends CompletableSource> mapper) {
@@ -15071,6 +15245,7 @@ <R> Flowable<R> switchMap0(Function<? super T, ? extends Publisher<? extends R>>
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> switchMapMaybe(@NonNull Function<? super T, ? extends MaybeSource<? extends R>> mapper) {
@@ -15101,6 +15276,7 @@ public final <R> Flowable<R> switchMapMaybe(@NonNull Function<? super T, ? exten
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> switchMapMaybeDelayError(@NonNull Function<? super T, ? extends MaybeSource<? extends R>> mapper) {
@@ -15141,6 +15317,7 @@ public final <R> Flowable<R> switchMapMaybeDelayError(@NonNull Function<? super
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> switchMapSingle(@NonNull Function<? super T, ? extends SingleSource<? extends R>> mapper) {
@@ -15171,6 +15348,7 @@ public final <R> Flowable<R> switchMapSingle(@NonNull Function<? super T, ? exte
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> switchMapSingleDelayError(@NonNull Function<? super T, ? extends SingleSource<? extends R>> mapper) {
@@ -15414,6 +15592,7 @@ public final Flowable<T> takeLast(long count, long time, TimeUnit unit, Schedule
      * @see <a href="http://reactivex.io/documentation/operators/takelast.html">ReactiveX operators documentation: TakeLast</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> takeLast(long count, long time, TimeUnit unit, Scheduler scheduler, boolean delayError, int bufferSize) {
@@ -15625,6 +15804,7 @@ public final Flowable<T> takeLast(long time, TimeUnit unit, Scheduler scheduler,
      * @since 1.1.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> takeUntil(Predicate<? super T> stopPredicate) {
@@ -15654,6 +15834,7 @@ public final Flowable<T> takeUntil(Predicate<? super T> stopPredicate) {
      * @see <a href="http://reactivex.io/documentation/operators/takeuntil.html">ReactiveX operators documentation: TakeUntil</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<T> takeUntil(Publisher<U> other) {
@@ -15682,6 +15863,7 @@ public final <U> Flowable<T> takeUntil(Publisher<U> other) {
      * @see Flowable#takeUntil(Predicate)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> takeWhile(Predicate<? super T> predicate) {
@@ -15746,6 +15928,7 @@ public final Flowable<T> throttleFirst(long windowDuration, TimeUnit unit) {
      * @see <a href="https://github.com/ReactiveX/RxJava/wiki/Backpressure">RxJava wiki: Backpressure</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> throttleFirst(long skipDuration, TimeUnit unit, Scheduler scheduler) {
@@ -15965,6 +16148,7 @@ public final Flowable<T> throttleLatest(long timeout, TimeUnit unit, Scheduler s
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> throttleLatest(long timeout, TimeUnit unit, Scheduler scheduler, boolean emitLast) {
@@ -16218,6 +16402,7 @@ public final <V> Flowable<T> timeout(Function<? super T, ? extends Publisher<V>>
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <V> Flowable<T> timeout(Function<? super T, ? extends Publisher<V>> itemTimeoutIndicator, Flowable<? extends T> other) {
@@ -16280,6 +16465,7 @@ public final Flowable<T> timeout(long timeout, TimeUnit timeUnit) {
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.COMPUTATION)
     public final Flowable<T> timeout(long timeout, TimeUnit timeUnit, Publisher<? extends T> other) {
@@ -16316,6 +16502,7 @@ public final Flowable<T> timeout(long timeout, TimeUnit timeUnit, Publisher<? ex
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> timeout(long timeout, TimeUnit timeUnit, Scheduler scheduler, Publisher<? extends T> other) {
@@ -16387,6 +16574,7 @@ public final Flowable<T> timeout(long timeout, TimeUnit timeUnit, Scheduler sche
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, V> Flowable<T> timeout(Publisher<U> firstTimeoutIndicator,
@@ -16432,6 +16620,7 @@ public final <U, V> Flowable<T> timeout(Publisher<U> firstTimeoutIndicator,
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, V> Flowable<T> timeout(
@@ -16556,6 +16745,7 @@ public final Flowable<Timed<T>> timestamp(TimeUnit unit) {
      * @see <a href="http://reactivex.io/documentation/operators/timestamp.html">ReactiveX operators documentation: Timestamp</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE) // Supplied scheduler is only used for creating timestamps.
     public final Flowable<Timed<T>> timestamp(final TimeUnit unit, final Scheduler scheduler) {
@@ -16726,6 +16916,7 @@ public final <U extends Collection<? super T>> Single<U> toList(Callable<U> coll
      * @see <a href="http://reactivex.io/documentation/operators/to.html">ReactiveX operators documentation: To</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K> Single<Map<K, T>> toMap(final Function<? super T, ? extends K> keySelector) {
@@ -16764,6 +16955,7 @@ public final <K> Single<Map<K, T>> toMap(final Function<? super T, ? extends K>
      * @see <a href="http://reactivex.io/documentation/operators/to.html">ReactiveX operators documentation: To</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K, V> Single<Map<K, V>> toMap(final Function<? super T, ? extends K> keySelector, final Function<? super T, ? extends V> valueSelector) {
@@ -16802,6 +16994,7 @@ public final <K, V> Single<Map<K, V>> toMap(final Function<? super T, ? extends
      * @see <a href="http://reactivex.io/documentation/operators/to.html">ReactiveX operators documentation: To</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K, V> Single<Map<K, V>> toMap(final Function<? super T, ? extends K> keySelector,
@@ -16915,6 +17108,7 @@ public final <K, V> Single<Map<K, Collection<V>>> toMultimap(Function<? super T,
      * @see <a href="http://reactivex.io/documentation/operators/to.html">ReactiveX operators documentation: To</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <K, V> Single<Map<K, Collection<V>>> toMultimap(
@@ -17046,6 +17240,7 @@ public final Single<List<T>> toSortedList() {
      * @see <a href="http://reactivex.io/documentation/operators/to.html">ReactiveX operators documentation: To</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<List<T>> toSortedList(final Comparator<? super T> comparator) {
@@ -17081,6 +17276,7 @@ public final Single<List<T>> toSortedList(final Comparator<? super T> comparator
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<List<T>> toSortedList(final Comparator<? super T> comparator, int capacityHint) {
@@ -17142,6 +17338,7 @@ public final Single<List<T>> toSortedList(int capacityHint) {
      * @see <a href="http://reactivex.io/documentation/operators/subscribeon.html">ReactiveX operators documentation: SubscribeOn</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<T> unsubscribeOn(Scheduler scheduler) {
@@ -17352,6 +17549,7 @@ public final Flowable<Flowable<T>> window(long timespan, long timeskip, TimeUnit
      * @see <a href="http://reactivex.io/documentation/operators/window.html">ReactiveX operators documentation: Window</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<Flowable<T>> window(long timespan, long timeskip, TimeUnit unit, Scheduler scheduler, int bufferSize) {
@@ -17630,6 +17828,7 @@ public final Flowable<Flowable<T>> window(long timespan, TimeUnit unit,
      * @see <a href="http://reactivex.io/documentation/operators/window.html">ReactiveX operators documentation: Window</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Flowable<Flowable<T>> window(
@@ -17698,6 +17897,7 @@ public final <B> Flowable<Flowable<T>> window(Publisher<B> boundaryIndicator) {
      * @see <a href="http://reactivex.io/documentation/operators/window.html">ReactiveX operators documentation: Window</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <B> Flowable<Flowable<T>> window(Publisher<B> boundaryIndicator, int bufferSize) {
@@ -17774,6 +17974,7 @@ public final <U, V> Flowable<Flowable<T>> window(
      * @see <a href="http://reactivex.io/documentation/operators/window.html">ReactiveX operators documentation: Window</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, V> Flowable<Flowable<T>> window(
@@ -17847,6 +18048,7 @@ public final <B> Flowable<Flowable<T>> window(Callable<? extends Publisher<B>> b
      * @see <a href="http://reactivex.io/documentation/operators/window.html">ReactiveX operators documentation: Window</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.ERROR)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <B> Flowable<Flowable<T>> window(Callable<? extends Publisher<B>> boundaryIndicatorSupplier, int bufferSize) {
@@ -17884,6 +18086,7 @@ public final <B> Flowable<Flowable<T>> window(Callable<? extends Publisher<B>> b
      * @see <a href="http://reactivex.io/documentation/operators/combinelatest.html">ReactiveX operators documentation: CombineLatest</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Flowable<R> withLatestFrom(Publisher<? extends U> other,
@@ -17921,6 +18124,7 @@ public final <U, R> Flowable<R> withLatestFrom(Publisher<? extends U> other,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T1, T2, R> Flowable<R> withLatestFrom(Publisher<T1> source1, Publisher<T2> source2,
@@ -17960,6 +18164,7 @@ public final <T1, T2, R> Flowable<R> withLatestFrom(Publisher<T1> source1, Publi
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T1, T2, T3, R> Flowable<R> withLatestFrom(
@@ -18004,6 +18209,7 @@ public final <T1, T2, T3, R> Flowable<R> withLatestFrom(
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <T1, T2, T3, T4, R> Flowable<R> withLatestFrom(
@@ -18042,6 +18248,7 @@ public final <T1, T2, T3, T4, R> Flowable<R> withLatestFrom(
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> withLatestFrom(Publisher<?>[] others, Function<? super Object[], R> combiner) {
@@ -18074,6 +18281,7 @@ public final <R> Flowable<R> withLatestFrom(Publisher<?>[] others, Function<? su
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.PASS_THROUGH)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> withLatestFrom(Iterable<? extends Publisher<?>> others, Function<? super Object[], R> combiner) {
@@ -18113,6 +18321,7 @@ public final <R> Flowable<R> withLatestFrom(Iterable<? extends Publisher<?>> oth
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Flowable<R> zipWith(Iterable<U> other,  BiFunction<? super T, ? super U, ? extends R> zipper) {
@@ -18161,6 +18370,7 @@ public final <U, R> Flowable<R> zipWith(Iterable<U> other,  BiFunction<? super T
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Flowable<R> zipWith(Publisher<? extends U> other, BiFunction<? super T, ? super U, ? extends R> zipper) {
diff --git a/src/main/java/io/reactivex/Maybe.java b/src/main/java/io/reactivex/Maybe.java
index b1d34260f1..773021a028 100644
--- a/src/main/java/io/reactivex/Maybe.java
+++ b/src/main/java/io/reactivex/Maybe.java
@@ -124,6 +124,7 @@ public abstract class Maybe<T> implements MaybeSource<T> {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> amb(final Iterable<? extends MaybeSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -174,6 +175,7 @@ public static <T> Maybe<T> ambArray(final MaybeSource<? extends T>... sources) {
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(Iterable<? extends MaybeSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -201,6 +203,7 @@ public static <T> Flowable<T> concat(Iterable<? extends MaybeSource<? extends T>
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> concat(MaybeSource<? extends T> source1, MaybeSource<? extends T> source2) {
@@ -232,6 +235,7 @@ public static <T> Flowable<T> concat(MaybeSource<? extends T> source1, MaybeSour
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> concat(
@@ -267,6 +271,7 @@ public static <T> Flowable<T> concat(
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> concat(
@@ -322,6 +327,7 @@ public static <T> Flowable<T> concat(Publisher<? extends MaybeSource<? extends T
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Flowable<T> concat(Publisher<? extends MaybeSource<? extends T>> sources, int prefetch) {
@@ -346,6 +352,7 @@ public static <T> Flowable<T> concat(Publisher<? extends MaybeSource<? extends T
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> concatArray(MaybeSource<? extends T>... sources) {
@@ -434,6 +441,7 @@ public static <T> Flowable<T> concatArrayEager(MaybeSource<? extends T>... sourc
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concatDelayError(Iterable<? extends MaybeSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -557,6 +565,7 @@ public static <T> Flowable<T> concatEager(Publisher<? extends MaybeSource<? exte
      * @see Cancellable
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> create(MaybeOnSubscribe<T> onSubscribe) {
         ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
@@ -576,6 +585,7 @@ public static <T> Maybe<T> create(MaybeOnSubscribe<T> onSubscribe) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> defer(final Callable<? extends MaybeSource<? extends T>> maybeSupplier) {
         ObjectHelper.requireNonNull(maybeSupplier, "maybeSupplier is null");
@@ -620,6 +630,7 @@ public static <T> Maybe<T> empty() {
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> error(Throwable exception) {
         ObjectHelper.requireNonNull(exception, "exception is null");
@@ -645,6 +656,7 @@ public static <T> Maybe<T> error(Throwable exception) {
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> error(Callable<? extends Throwable> supplier) {
         ObjectHelper.requireNonNull(supplier, "errorSupplier is null");
@@ -671,6 +683,7 @@ public static <T> Maybe<T> error(Callable<? extends Throwable> supplier) {
      * @throws NullPointerException if run is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromAction(final Action run) {
         ObjectHelper.requireNonNull(run, "run is null");
@@ -690,6 +703,7 @@ public static <T> Maybe<T> fromAction(final Action run) {
      * @throws NullPointerException if completable is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromCompletable(CompletableSource completableSource) {
         ObjectHelper.requireNonNull(completableSource, "completableSource is null");
@@ -709,6 +723,7 @@ public static <T> Maybe<T> fromCompletable(CompletableSource completableSource)
      * @throws NullPointerException if single is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromSingle(SingleSource<T> singleSource) {
         ObjectHelper.requireNonNull(singleSource, "singleSource is null");
@@ -750,6 +765,7 @@ public static <T> Maybe<T> fromSingle(SingleSource<T> singleSource) {
      * @return a new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromCallable(@NonNull final Callable<? extends T> callable) {
         ObjectHelper.requireNonNull(callable, "callable is null");
@@ -783,6 +799,7 @@ public static <T> Maybe<T> fromCallable(@NonNull final Callable<? extends T> cal
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromFuture(Future<? extends T> future) {
         ObjectHelper.requireNonNull(future, "future is null");
@@ -820,6 +837,7 @@ public static <T> Maybe<T> fromFuture(Future<? extends T> future) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromFuture(Future<? extends T> future, long timeout, TimeUnit unit) {
         ObjectHelper.requireNonNull(future, "future is null");
@@ -840,6 +858,7 @@ public static <T> Maybe<T> fromFuture(Future<? extends T> future, long timeout,
      * @throws NullPointerException if run is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> fromRunnable(final Runnable run) {
         ObjectHelper.requireNonNull(run, "run is null");
@@ -866,6 +885,7 @@ public static <T> Maybe<T> fromRunnable(final Runnable run) {
      * @see <a href="http://reactivex.io/documentation/operators/just.html">ReactiveX operators documentation: Just</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> just(T item) {
         ObjectHelper.requireNonNull(item, "item is null");
@@ -970,6 +990,7 @@ public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>> sources, int maxConcurrency) {
@@ -1002,6 +1023,7 @@ public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>
      * @see <a href="http://reactivex.io/documentation/operators/merge.html">ReactiveX operators documentation: Merge</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Maybe<T> merge(MaybeSource<? extends MaybeSource<? extends T>> source) {
@@ -1047,6 +1069,7 @@ public static <T> Maybe<T> merge(MaybeSource<? extends MaybeSource<? extends T>>
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> merge(
@@ -1097,6 +1120,7 @@ public static <T> Flowable<T> merge(
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> merge(
@@ -1151,6 +1175,7 @@ public static <T> Flowable<T> merge(
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> merge(
@@ -1193,6 +1218,7 @@ public static <T> Flowable<T> merge(
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T> Flowable<T> mergeArray(MaybeSource<? extends T>... sources) {
@@ -1347,6 +1373,7 @@ public static <T> Flowable<T> mergeDelayError(Publisher<? extends MaybeSource<?
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(Publisher<? extends MaybeSource<? extends T>> sources, int maxConcurrency) {
         ObjectHelper.requireNonNull(sources, "source is null");
@@ -1385,6 +1412,7 @@ public static <T> Flowable<T> mergeDelayError(Publisher<? extends MaybeSource<?
     @SuppressWarnings({ "unchecked" })
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(MaybeSource<? extends T> source1, MaybeSource<? extends T> source2) {
         ObjectHelper.requireNonNull(source1, "source1 is null");
@@ -1426,6 +1454,7 @@ public static <T> Flowable<T> mergeDelayError(MaybeSource<? extends T> source1,
     @SuppressWarnings({ "unchecked" })
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(MaybeSource<? extends T> source1,
             MaybeSource<? extends T> source2, MaybeSource<? extends T> source3) {
@@ -1471,6 +1500,7 @@ public static <T> Flowable<T> mergeDelayError(MaybeSource<? extends T> source1,
     @SuppressWarnings({ "unchecked" })
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(
             MaybeSource<? extends T> source1, MaybeSource<? extends T> source2,
@@ -1554,6 +1584,7 @@ public static <T> Single<Boolean> sequenceEqual(MaybeSource<? extends T> source1
      * @see <a href="http://reactivex.io/documentation/operators/sequenceequal.html">ReactiveX operators documentation: SequenceEqual</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<Boolean> sequenceEqual(MaybeSource<? extends T> source1, MaybeSource<? extends T> source2,
             BiPredicate<? super T, ? super T> isEqual) {
@@ -1604,6 +1635,7 @@ public static Maybe<Long> timer(long delay, TimeUnit unit) {
      * @see <a href="http://reactivex.io/documentation/operators/timer.html">ReactiveX operators documentation: Timer</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Maybe<Long> timer(long delay, TimeUnit unit, Scheduler scheduler) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -1624,6 +1656,7 @@ public static Maybe<Long> timer(long delay, TimeUnit unit, Scheduler scheduler)
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> unsafeCreate(MaybeSource<T> onSubscribe) {
         if (onSubscribe instanceof Maybe) {
@@ -1690,6 +1723,7 @@ public static <T, D> Maybe<T> using(Callable<? extends D> resourceSupplier,
      * @see <a href="http://reactivex.io/documentation/operators/using.html">ReactiveX operators documentation: Using</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, D> Maybe<T> using(Callable<? extends D> resourceSupplier,
             Function<? super D, ? extends MaybeSource<? extends T>> sourceSupplier,
@@ -1712,6 +1746,7 @@ public static <T, D> Maybe<T> using(Callable<? extends D> resourceSupplier,
      * @return the Maybe wrapper or the source cast to Maybe (if possible)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Maybe<T> wrap(MaybeSource<T> source) {
         if (source instanceof Maybe) {
@@ -1749,6 +1784,7 @@ public static <T> Maybe<T> wrap(MaybeSource<T> source) {
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Maybe<R> zip(Iterable<? extends MaybeSource<? extends T>> sources, Function<? super Object[], ? extends R> zipper) {
         ObjectHelper.requireNonNull(zipper, "zipper is null");
@@ -1783,6 +1819,7 @@ public static <T, R> Maybe<R> zip(Iterable<? extends MaybeSource<? extends T>> s
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2,
@@ -1822,6 +1859,7 @@ public static <T1, T2, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -1865,6 +1903,7 @@ public static <T1, T2, T3, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -1913,6 +1952,7 @@ public static <T1, T2, T3, T4, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -1965,6 +2005,7 @@ public static <T1, T2, T3, T4, T5, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -2021,6 +2062,7 @@ public static <T1, T2, T3, T4, T5, T6, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -2082,6 +2124,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -2147,6 +2190,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Maybe<R> zip(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Maybe<R> zip(
             MaybeSource<? extends T1> source1, MaybeSource<? extends T2> source2, MaybeSource<? extends T3> source3,
@@ -2194,6 +2238,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Maybe<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Maybe<R> zipArray(Function<? super Object[], ? extends R> zipper,
             MaybeSource<? extends T>... sources) {
@@ -2227,6 +2272,7 @@ public static <T, R> Maybe<R> zipArray(Function<? super Object[], ? extends R> z
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> ambWith(MaybeSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2335,6 +2381,7 @@ public final Maybe<T> cache() {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<U> cast(final Class<? extends U> clazz) {
         ObjectHelper.requireNonNull(clazz, "clazz is null");
@@ -2383,6 +2430,7 @@ public final <R> Maybe<R> compose(MaybeTransformer<? super T, ? extends R> trans
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> concatMap(Function<? super T, ? extends MaybeSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2409,6 +2457,7 @@ public final <R> Maybe<R> concatMap(Function<? super T, ? extends MaybeSource<?
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> concatWith(MaybeSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2432,6 +2481,7 @@ public final Flowable<T> concatWith(MaybeSource<? extends T> other) {
      * @see <a href="http://reactivex.io/documentation/operators/contains.html">ReactiveX operators documentation: Contains</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<Boolean> contains(final Object item) {
         ObjectHelper.requireNonNull(item, "item is null");
@@ -2480,6 +2530,7 @@ public final Single<Long> count() {
      * @see <a href="http://reactivex.io/documentation/operators/defaultifempty.html">ReactiveX operators documentation: DefaultIfEmpty</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> defaultIfEmpty(T defaultItem) {
         ObjectHelper.requireNonNull(defaultItem, "item is null");
@@ -2529,6 +2580,7 @@ public final Maybe<T> delay(long delay, TimeUnit unit) {
      * @see <a href="http://reactivex.io/documentation/operators/delay.html">ReactiveX operators documentation: Delay</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Maybe<T> delay(long delay, TimeUnit unit, Scheduler scheduler) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -2559,6 +2611,7 @@ public final Maybe<T> delay(long delay, TimeUnit unit, Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/delay.html">ReactiveX operators documentation: Delay</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     public final <U, V> Maybe<T> delay(Publisher<U> delayIndicator) {
@@ -2584,6 +2637,7 @@ public final <U, V> Maybe<T> delay(Publisher<U> delayIndicator) {
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> delaySubscription(Publisher<U> subscriptionIndicator) {
         ObjectHelper.requireNonNull(subscriptionIndicator, "subscriptionIndicator is null");
@@ -2652,6 +2706,7 @@ public final Maybe<T> delaySubscription(long delay, TimeUnit unit, Scheduler sch
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
         ObjectHelper.requireNonNull(onAfterSuccess, "doAfterSuccess is null");
@@ -2676,6 +2731,7 @@ public final Maybe<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doAfterTerminate(Action onAfterTerminate) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2705,6 +2761,7 @@ public final Maybe<T> doAfterTerminate(Action onAfterTerminate) {
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doFinally(Action onFinally) {
         ObjectHelper.requireNonNull(onFinally, "onFinally is null");
@@ -2723,6 +2780,7 @@ public final Maybe<T> doFinally(Action onFinally) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doOnDispose(Action onDispose) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2750,6 +2808,7 @@ public final Maybe<T> doOnDispose(Action onDispose) {
      * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doOnComplete(Action onComplete) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2775,6 +2834,7 @@ public final Maybe<T> doOnComplete(Action onComplete) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doOnError(Consumer<? super Throwable> onError) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2819,6 +2879,7 @@ public final Maybe<T> doOnEvent(BiConsumer<? super T, ? super Throwable> onEvent
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doOnSubscribe(Consumer<? super Disposable> onSubscribe) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2844,6 +2905,7 @@ public final Maybe<T> doOnSubscribe(Consumer<? super Disposable> onSubscribe) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> doOnSuccess(Consumer<? super T> onSuccess) {
         return RxJavaPlugins.onAssembly(new MaybePeek<T>(this,
@@ -2874,6 +2936,7 @@ public final Maybe<T> doOnSuccess(Consumer<? super T> onSuccess) {
      * @see <a href="http://reactivex.io/documentation/operators/filter.html">ReactiveX operators documentation: Filter</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> filter(Predicate<? super T> predicate) {
         ObjectHelper.requireNonNull(predicate, "predicate is null");
@@ -2898,6 +2961,7 @@ public final Maybe<T> filter(Predicate<? super T> predicate) {
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2926,6 +2990,7 @@ public final <R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<? ex
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> flatMap(
             Function<? super T, ? extends MaybeSource<? extends R>> onSuccessMapper,
@@ -2960,6 +3025,7 @@ public final <R> Maybe<R> flatMap(
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<? extends U>> mapper,
             BiFunction<? super T, ? super U, ? extends R> resultSelector) {
@@ -2990,6 +3056,7 @@ public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<?
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3014,6 +3081,7 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3037,6 +3105,7 @@ public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? e
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Observable<R> flatMapObservable(Function<? super T, ? extends ObservableSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3064,6 +3133,7 @@ public final <R> Observable<R> flatMapObservable(Function<? super T, ? extends O
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publisher<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3089,6 +3159,7 @@ public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publ
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> flatMapSingle(final Function<? super T, ? extends SingleSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3116,6 +3187,7 @@ public final <R> Single<R> flatMapSingle(final Function<? super T, ? extends Sin
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> flatMapSingleElement(final Function<? super T, ? extends SingleSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3139,6 +3211,7 @@ public final <R> Maybe<R> flatMapSingleElement(final Function<? super T, ? exten
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable flatMapCompletable(final Function<? super T, ? extends CompletableSource> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3348,6 +3421,7 @@ public final Single<Boolean> isEmpty() {
      * @see #compose(MaybeTransformer)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> lift(final MaybeOperator<? extends R, ? super T> lift) {
         ObjectHelper.requireNonNull(lift, "onLift is null");
@@ -3371,6 +3445,7 @@ public final <R> Maybe<R> lift(final MaybeOperator<? extends R, ? super T> lift)
      * @see <a href="http://reactivex.io/documentation/operators/map.html">ReactiveX operators documentation: Map</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> map(Function<? super T, ? extends R> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -3418,6 +3493,7 @@ public final Single<Notification<T>> materialize() {
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Flowable<T> mergeWith(MaybeSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3443,6 +3519,7 @@ public final Flowable<T> mergeWith(MaybeSource<? extends T> other) {
      * @see #subscribeOn
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Maybe<T> observeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -3466,6 +3543,7 @@ public final Maybe<T> observeOn(final Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/filter.html">ReactiveX operators documentation: Filter</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<U> ofType(final Class<U> clazz) {
         ObjectHelper.requireNonNull(clazz, "clazz is null");
@@ -3486,6 +3564,7 @@ public final <U> Maybe<U> ofType(final Class<U> clazz) {
      * @return the value returned by the convert function
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> R to(Function<? super Maybe<T>, R> convert) {
         try {
@@ -3549,6 +3628,7 @@ public final Observable<T> toObservable() {
      * @return the new Single instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> toSingle(T defaultValue) {
         ObjectHelper.requireNonNull(defaultValue, "defaultValue is null");
@@ -3597,6 +3677,7 @@ public final Maybe<T> onErrorComplete() {
      * @return the new Completable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onErrorComplete(final Predicate<? super Throwable> predicate) {
         ObjectHelper.requireNonNull(predicate, "predicate is null");
@@ -3624,6 +3705,7 @@ public final Maybe<T> onErrorComplete(final Predicate<? super Throwable> predica
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onErrorResumeNext(final MaybeSource<? extends T> next) {
         ObjectHelper.requireNonNull(next, "next is null");
@@ -3650,6 +3732,7 @@ public final Maybe<T> onErrorResumeNext(final MaybeSource<? extends T> next) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onErrorResumeNext(Function<? super Throwable, ? extends MaybeSource<? extends T>> resumeFunction) {
         ObjectHelper.requireNonNull(resumeFunction, "resumeFunction is null");
@@ -3676,6 +3759,7 @@ public final Maybe<T> onErrorResumeNext(Function<? super Throwable, ? extends Ma
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onErrorReturn(Function<? super Throwable, ? extends T> valueSupplier) {
         ObjectHelper.requireNonNull(valueSupplier, "valueSupplier is null");
@@ -3701,6 +3785,7 @@ public final Maybe<T> onErrorReturn(Function<? super Throwable, ? extends T> val
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onErrorReturnItem(final T item) {
         ObjectHelper.requireNonNull(item, "item is null");
@@ -3730,6 +3815,7 @@ public final Maybe<T> onErrorReturnItem(final T item) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> onExceptionResumeNext(final MaybeSource<? extends T> next) {
         ObjectHelper.requireNonNull(next, "next is null");
@@ -3970,6 +4056,7 @@ public final Maybe<T> retry(Predicate<? super Throwable> predicate) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> retryUntil(final BooleanSupplier stop) {
         ObjectHelper.requireNonNull(stop, "stop is null");
@@ -4152,6 +4239,7 @@ public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? supe
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? super Throwable> onError,
             Action onComplete) {
@@ -4208,6 +4296,7 @@ public final void subscribe(MaybeObserver<? super T> observer) {
      * @see #observeOn
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Maybe<T> subscribeOn(Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -4260,6 +4349,7 @@ public final <E extends MaybeObserver<? super T>> E subscribeWith(E observer) {
      *          alternate MaybeSource if the source Maybe is empty.
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> switchIfEmpty(MaybeSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -4283,6 +4373,7 @@ public final Maybe<T> switchIfEmpty(MaybeSource<? extends T> other) {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> switchIfEmpty(SingleSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -4308,6 +4399,7 @@ public final Single<T> switchIfEmpty(SingleSource<? extends T> other) {
      * @see <a href="http://reactivex.io/documentation/operators/takeuntil.html">ReactiveX operators documentation: TakeUntil</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> takeUntil(MaybeSource<U> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -4337,6 +4429,7 @@ public final <U> Maybe<T> takeUntil(MaybeSource<U> other) {
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> takeUntil(Publisher<U> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -4388,6 +4481,7 @@ public final Maybe<T> timeout(long timeout, TimeUnit timeUnit) {
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.COMPUTATION)
     public final Maybe<T> timeout(long timeout, TimeUnit timeUnit, MaybeSource<? extends T> fallback) {
         ObjectHelper.requireNonNull(fallback, "other is null");
@@ -4417,6 +4511,7 @@ public final Maybe<T> timeout(long timeout, TimeUnit timeUnit, MaybeSource<? ext
      * @see <a href="http://reactivex.io/documentation/operators/timeout.html">ReactiveX operators documentation: Timeout</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Maybe<T> timeout(long timeout, TimeUnit timeUnit, Scheduler scheduler, MaybeSource<? extends T> fallback) {
         ObjectHelper.requireNonNull(fallback, "fallback is null");
@@ -4463,6 +4558,7 @@ public final Maybe<T> timeout(long timeout, TimeUnit timeUnit, Scheduler schedul
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> timeout(MaybeSource<U> timeoutIndicator) {
         ObjectHelper.requireNonNull(timeoutIndicator, "timeoutIndicator is null");
@@ -4484,6 +4580,7 @@ public final <U> Maybe<T> timeout(MaybeSource<U> timeoutIndicator) {
      * @return the new Maybe instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> timeout(MaybeSource<U> timeoutIndicator, MaybeSource<? extends T> fallback) {
         ObjectHelper.requireNonNull(timeoutIndicator, "timeoutIndicator is null");
@@ -4508,6 +4605,7 @@ public final <U> Maybe<T> timeout(MaybeSource<U> timeoutIndicator, MaybeSource<?
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> timeout(Publisher<U> timeoutIndicator) {
         ObjectHelper.requireNonNull(timeoutIndicator, "timeoutIndicator is null");
@@ -4533,6 +4631,7 @@ public final <U> Maybe<T> timeout(Publisher<U> timeoutIndicator) {
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Maybe<T> timeout(Publisher<U> timeoutIndicator, MaybeSource<? extends T> fallback) {
         ObjectHelper.requireNonNull(timeoutIndicator, "timeoutIndicator is null");
@@ -4552,6 +4651,7 @@ public final <U> Maybe<T> timeout(Publisher<U> timeoutIndicator, MaybeSource<? e
      * @throws NullPointerException if scheduler is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Maybe<T> unsubscribeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -4585,6 +4685,7 @@ public final Maybe<T> unsubscribeOn(final Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Maybe<R> zipWith(MaybeSource<? extends U> other, BiFunction<? super T, ? super U, ? extends R> zipper) {
         ObjectHelper.requireNonNull(other, "other is null");
diff --git a/src/main/java/io/reactivex/Observable.java b/src/main/java/io/reactivex/Observable.java
index 541c20b1f4..fdd8b29a92 100644
--- a/src/main/java/io/reactivex/Observable.java
+++ b/src/main/java/io/reactivex/Observable.java
@@ -116,6 +116,7 @@ public abstract class Observable<T> implements ObservableSource<T> {
      * @see <a href="http://reactivex.io/documentation/operators/amb.html">ReactiveX operators documentation: Amb</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> amb(Iterable<? extends ObservableSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -142,6 +143,7 @@ public static <T> Observable<T> amb(Iterable<? extends ObservableSource<? extend
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> ambArray(ObservableSource<? extends T>... sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -289,6 +291,7 @@ public static <T, R> Observable<R> combineLatest(Iterable<? extends ObservableSo
      * @see <a href="http://reactivex.io/documentation/operators/combinelatest.html">ReactiveX operators documentation: CombineLatest</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Observable<R> combineLatest(Iterable<? extends ObservableSource<? extends T>> sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -381,6 +384,7 @@ public static <T, R> Observable<R> combineLatest(ObservableSource<? extends T>[]
      * @see <a href="http://reactivex.io/documentation/operators/combinelatest.html">ReactiveX operators documentation: CombineLatest</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Observable<R> combineLatest(ObservableSource<? extends T>[] sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -426,6 +430,7 @@ public static <T, R> Observable<R> combineLatest(ObservableSource<? extends T>[]
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -468,6 +473,7 @@ public static <T1, T2, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -515,6 +521,7 @@ public static <T1, T2, T3, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -566,6 +573,7 @@ public static <T1, T2, T3, T4, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -622,6 +630,7 @@ public static <T1, T2, T3, T4, T5, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -682,6 +691,7 @@ public static <T1, T2, T3, T4, T5, T6, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -747,6 +757,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -816,6 +827,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Observable<R> combineLatest(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Observable<R> combineLatest(
             ObservableSource<? extends T1> source1, ObservableSource<? extends T2> source2,
@@ -962,6 +974,7 @@ public static <T, R> Observable<R> combineLatestDelayError(Function<? super Obje
      * @see <a href="http://reactivex.io/documentation/operators/combinelatest.html">ReactiveX operators documentation: CombineLatest</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Observable<R> combineLatestDelayError(ObservableSource<? extends T>[] sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -1057,6 +1070,7 @@ public static <T, R> Observable<R> combineLatestDelayError(Iterable<? extends Ob
      * @see <a href="http://reactivex.io/documentation/operators/combinelatest.html">ReactiveX operators documentation: CombineLatest</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Observable<R> combineLatestDelayError(Iterable<? extends ObservableSource<? extends T>> sources,
             Function<? super Object[], ? extends R> combiner, int bufferSize) {
@@ -1084,6 +1098,7 @@ public static <T, R> Observable<R> combineLatestDelayError(Iterable<? extends Ob
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concat(Iterable<? extends ObservableSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -1134,6 +1149,7 @@ public static <T> Observable<T> concat(ObservableSource<? extends ObservableSour
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concat(ObservableSource<? extends ObservableSource<? extends T>> sources, int prefetch) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -1162,6 +1178,7 @@ public static <T> Observable<T> concat(ObservableSource<? extends ObservableSour
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concat(ObservableSource<? extends T> source1, ObservableSource<? extends T> source2) {
         ObjectHelper.requireNonNull(source1, "source1 is null");
@@ -1192,6 +1209,7 @@ public static <T> Observable<T> concat(ObservableSource<? extends T> source1, Ob
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concat(
             ObservableSource<? extends T> source1, ObservableSource<? extends T> source2,
@@ -1227,6 +1245,7 @@ public static <T> Observable<T> concat(
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concat(
             ObservableSource<? extends T> source1, ObservableSource<? extends T> source2,
@@ -1410,6 +1429,7 @@ public static <T> Observable<T> concatArrayEagerDelayError(int maxConcurrency, i
      * @return the new ObservableSource with the concatenating behavior
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concatDelayError(Iterable<? extends ObservableSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -1455,6 +1475,7 @@ public static <T> Observable<T> concatDelayError(ObservableSource<? extends Obse
      */
     @SuppressWarnings({ "rawtypes", "unchecked" })
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> concatDelayError(ObservableSource<? extends ObservableSource<? extends T>> sources, int prefetch, boolean tillTheEnd) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -1607,6 +1628,7 @@ public static <T> Observable<T> concatEager(Iterable<? extends ObservableSource<
      * @see Cancellable
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> create(ObservableOnSubscribe<T> source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -1638,6 +1660,7 @@ public static <T> Observable<T> create(ObservableOnSubscribe<T> source) {
      * @see <a href="http://reactivex.io/documentation/operators/defer.html">ReactiveX operators documentation: Defer</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> defer(Callable<? extends ObservableSource<? extends T>> supplier) {
         ObjectHelper.requireNonNull(supplier, "supplier is null");
@@ -1686,6 +1709,7 @@ public static <T> Observable<T> empty() {
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> error(Callable<? extends Throwable> errorSupplier) {
         ObjectHelper.requireNonNull(errorSupplier, "errorSupplier is null");
@@ -1711,6 +1735,7 @@ public static <T> Observable<T> error(Callable<? extends Throwable> errorSupplie
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> error(final Throwable exception) {
         ObjectHelper.requireNonNull(exception, "e is null");
@@ -1735,6 +1760,7 @@ public static <T> Observable<T> error(final Throwable exception) {
      */
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
+    @NonNull
     public static <T> Observable<T> fromArray(T... items) {
         ObjectHelper.requireNonNull(items, "items is null");
         if (items.length == 0) {
@@ -1775,6 +1801,7 @@ public static <T> Observable<T> fromArray(T... items) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> fromCallable(Callable<? extends T> supplier) {
         ObjectHelper.requireNonNull(supplier, "supplier is null");
@@ -1808,6 +1835,7 @@ public static <T> Observable<T> fromCallable(Callable<? extends T> supplier) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> fromFuture(Future<? extends T> future) {
         ObjectHelper.requireNonNull(future, "future is null");
@@ -1845,6 +1873,7 @@ public static <T> Observable<T> fromFuture(Future<? extends T> future) {
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> fromFuture(Future<? extends T> future, long timeout, TimeUnit unit) {
         ObjectHelper.requireNonNull(future, "future is null");
@@ -1886,6 +1915,7 @@ public static <T> Observable<T> fromFuture(Future<? extends T> future, long time
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static <T> Observable<T> fromFuture(Future<? extends T> future, long timeout, TimeUnit unit, Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -1921,6 +1951,7 @@ public static <T> Observable<T> fromFuture(Future<? extends T> future, long time
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static <T> Observable<T> fromFuture(Future<? extends T> future, Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -1946,6 +1977,7 @@ public static <T> Observable<T> fromFuture(Future<? extends T> future, Scheduler
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> fromIterable(Iterable<? extends T> source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -1982,6 +2014,7 @@ public static <T> Observable<T> fromIterable(Iterable<? extends T> source) {
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> fromPublisher(Publisher<? extends T> publisher) {
         ObjectHelper.requireNonNull(publisher, "publisher is null");
@@ -2010,6 +2043,7 @@ public static <T> Observable<T> fromPublisher(Publisher<? extends T> publisher)
      * @return the new Observable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> generate(final Consumer<Emitter<T>> generator) {
         ObjectHelper.requireNonNull(generator, "generator  is null");
@@ -2041,6 +2075,7 @@ public static <T> Observable<T> generate(final Consumer<Emitter<T>> generator) {
      * @return the new Observable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Observable<T> generate(Callable<S> initialState, final BiConsumer<S, Emitter<T>> generator) {
         ObjectHelper.requireNonNull(generator, "generator  is null");
@@ -2073,6 +2108,7 @@ public static <T, S> Observable<T> generate(Callable<S> initialState, final BiCo
      * @return the new Observable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Observable<T> generate(
             final Callable<S> initialState,
@@ -2139,6 +2175,7 @@ public static <T, S> Observable<T> generate(Callable<S> initialState, BiFunction
      * @return the new Observable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, S> Observable<T> generate(Callable<S> initialState, BiFunction<S, Emitter<T>, S> generator,
             Consumer<? super S> disposeState) {
@@ -2199,6 +2236,7 @@ public static Observable<Long> interval(long initialDelay, long period, TimeUnit
      * @since 1.0.12
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Observable<Long> interval(long initialDelay, long period, TimeUnit unit, Scheduler scheduler) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -2295,6 +2333,7 @@ public static Observable<Long> intervalRange(long start, long count, long initia
      * @return the new Observable instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Observable<Long> intervalRange(long start, long count, long initialDelay, long period, TimeUnit unit, Scheduler scheduler) {
         if (count < 0) {
@@ -2344,6 +2383,7 @@ public static Observable<Long> intervalRange(long start, long count, long initia
      * @see #fromIterable(Iterable)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item) {
         ObjectHelper.requireNonNull(item, "The item is null");
@@ -2370,6 +2410,7 @@ public static <T> Observable<T> just(T item) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2400,6 +2441,7 @@ public static <T> Observable<T> just(T item1, T item2) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2433,6 +2475,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2469,6 +2512,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4) {
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2508,6 +2552,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5, T item6) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2550,6 +2595,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2595,6 +2641,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2643,6 +2690,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8, T item9) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
@@ -2694,6 +2742,7 @@ public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5
      */
     @SuppressWarnings("unchecked")
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Observable<T> just(T item1, T item2, T item3, T item4, T item5, T item6, T item7, T item8, T item9, T item10) {
         ObjectHelper.requireNonNull(item1, "The first item is null");
diff --git a/src/main/java/io/reactivex/Single.java b/src/main/java/io/reactivex/Single.java
index 168c9c216a..f41d69a80c 100644
--- a/src/main/java/io/reactivex/Single.java
+++ b/src/main/java/io/reactivex/Single.java
@@ -129,6 +129,7 @@ public abstract class Single<T> implements SingleSource<T> {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> amb(final Iterable<? extends SingleSource<? extends T>> sources) {
         ObjectHelper.requireNonNull(sources, "sources is null");
@@ -180,6 +181,7 @@ public static <T> Single<T> ambArray(final SingleSource<? extends T>... sources)
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.FULL)
     public static <T> Flowable<T> concat(Iterable<? extends SingleSource<? extends T>> sources) {
@@ -201,6 +203,7 @@ public static <T> Flowable<T> concat(Iterable<? extends SingleSource<? extends T
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Observable<T> concat(ObservableSource<? extends SingleSource<? extends T>> sources) {
@@ -226,6 +229,7 @@ public static <T> Observable<T> concat(ObservableSource<? extends SingleSource<?
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concat(Publisher<? extends SingleSource<? extends T>> sources) {
@@ -251,6 +255,7 @@ public static <T> Flowable<T> concat(Publisher<? extends SingleSource<? extends
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
@@ -280,6 +285,7 @@ public static <T> Flowable<T> concat(Publisher<? extends SingleSource<? extends
      * @see <a href="http://reactivex.io/documentation/operators/concat.html">ReactiveX operators documentation: Concat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -313,6 +319,7 @@ public static <T> Flowable<T> concat(
      * @see <a href="http://reactivex.io/documentation/operators/concat.html">ReactiveX operators documentation: Concat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -350,6 +357,7 @@ public static <T> Flowable<T> concat(
      * @see <a href="http://reactivex.io/documentation/operators/concat.html">ReactiveX operators documentation: Concat</a>
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -381,6 +389,7 @@ public static <T> Flowable<T> concat(
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
@@ -406,6 +415,7 @@ public static <T> Flowable<T> concatArray(SingleSource<? extends T>... sources)
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concatArrayEager(SingleSource<? extends T>... sources) {
         return Flowable.fromArray(sources).concatMapEager(SingleInternalHelper.<T>toFlowable());
@@ -433,6 +443,7 @@ public static <T> Flowable<T> concatArrayEager(SingleSource<? extends T>... sour
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concatEager(Publisher<? extends SingleSource<? extends T>> sources) {
         return Flowable.fromPublisher(sources).concatMapEager(SingleInternalHelper.<T>toFlowable());
@@ -458,6 +469,7 @@ public static <T> Flowable<T> concatEager(Publisher<? extends SingleSource<? ext
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> concatEager(Iterable<? extends SingleSource<? extends T>> sources) {
         return Flowable.fromIterable(sources).concatMapEager(SingleInternalHelper.<T>toFlowable());
@@ -500,6 +512,7 @@ public static <T> Flowable<T> concatEager(Iterable<? extends SingleSource<? exte
      * @see Cancellable
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> create(SingleOnSubscribe<T> source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -521,6 +534,7 @@ public static <T> Single<T> create(SingleOnSubscribe<T> source) {
      * @return the new Single instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> defer(final Callable<? extends SingleSource<? extends T>> singleSupplier) {
         ObjectHelper.requireNonNull(singleSupplier, "singleSupplier is null");
@@ -541,6 +555,7 @@ public static <T> Single<T> defer(final Callable<? extends SingleSource<? extend
      * @return the new Single instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> error(final Callable<? extends Throwable> errorSupplier) {
         ObjectHelper.requireNonNull(errorSupplier, "errorSupplier is null");
@@ -566,6 +581,7 @@ public static <T> Single<T> error(final Callable<? extends Throwable> errorSuppl
      * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> error(final Throwable exception) {
         ObjectHelper.requireNonNull(exception, "error is null");
@@ -599,6 +615,7 @@ public static <T> Single<T> error(final Throwable exception) {
      * @return a {@link Single} whose {@link SingleObserver}s' subscriptions trigger an invocation of the given function.
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> fromCallable(final Callable<? extends T> callable) {
         ObjectHelper.requireNonNull(callable, "callable is null");
@@ -763,6 +780,7 @@ public static <T> Single<T> fromFuture(Future<? extends T> future, Scheduler sch
      */
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> fromPublisher(final Publisher<? extends T> publisher) {
         ObjectHelper.requireNonNull(publisher, "publisher is null");
@@ -786,6 +804,7 @@ public static <T> Single<T> fromPublisher(final Publisher<? extends T> publisher
      * @return the new Single instance
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> fromObservable(ObservableSource<? extends T> observableSource) {
         ObjectHelper.requireNonNull(observableSource, "observableSource is null");
@@ -813,6 +832,7 @@ public static <T> Single<T> fromObservable(ObservableSource<? extends T> observa
      */
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
+    @NonNull
     public static <T> Single<T> just(final T item) {
         ObjectHelper.requireNonNull(item, "value is null");
         return RxJavaPlugins.onAssembly(new SingleJust<T>(item));
@@ -849,6 +869,7 @@ public static <T> Single<T> just(final T item) {
      * @see #mergeDelayError(Iterable)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> merge(Iterable<? extends SingleSource<? extends T>> sources) {
@@ -886,6 +907,7 @@ public static <T> Flowable<T> merge(Iterable<? extends SingleSource<? extends T>
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
@@ -917,6 +939,7 @@ public static <T> Flowable<T> merge(Publisher<? extends SingleSource<? extends T
      * @see <a href="http://reactivex.io/documentation/operators/merge.html">ReactiveX operators documentation: Merge</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Single<T> merge(SingleSource<? extends SingleSource<? extends T>> source) {
@@ -961,6 +984,7 @@ public static <T> Single<T> merge(SingleSource<? extends SingleSource<? extends
      * @see #mergeDelayError(SingleSource, SingleSource)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1011,6 +1035,7 @@ public static <T> Flowable<T> merge(
      * @see #mergeDelayError(SingleSource, SingleSource, SingleSource)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1065,6 +1090,7 @@ public static <T> Flowable<T> merge(
      * @see #mergeDelayError(SingleSource, SingleSource, SingleSource, SingleSource)
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1096,6 +1122,7 @@ public static <T> Flowable<T> merge(
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeDelayError(Iterable<? extends SingleSource<? extends T>> sources) {
@@ -1119,6 +1146,7 @@ public static <T> Flowable<T> mergeDelayError(Iterable<? extends SingleSource<?
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
@@ -1153,6 +1181,7 @@ public static <T> Flowable<T> mergeDelayError(Publisher<? extends SingleSource<?
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1192,6 +1221,7 @@ public static <T> Flowable<T> mergeDelayError(
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1235,6 +1265,7 @@ public static <T> Flowable<T> mergeDelayError(
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
@@ -1305,6 +1336,7 @@ public static Single<Long> timer(long delay, TimeUnit unit) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public static Single<Long> timer(final long delay, final TimeUnit unit, final Scheduler scheduler) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -1327,6 +1359,7 @@ public static Single<Long> timer(final long delay, final TimeUnit unit, final Sc
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<Boolean> equals(final SingleSource<? extends T> first, final SingleSource<? extends T> second) { // NOPMD
         ObjectHelper.requireNonNull(first, "first is null");
@@ -1350,6 +1383,7 @@ public static <T> Single<Boolean> equals(final SingleSource<? extends T> first,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> unsafeCreate(SingleSource<T> onSubscribe) {
         ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
@@ -1409,6 +1443,7 @@ public static <T, U> Single<T> using(Callable<U> resourceSupplier,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, U> Single<T> using(
             final Callable<U> resourceSupplier,
@@ -1434,6 +1469,7 @@ public static <T, U> Single<T> using(
      * @return the Single wrapper or the source cast to Single (if possible)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<T> wrap(SingleSource<T> source) {
         ObjectHelper.requireNonNull(source, "source is null");
@@ -1473,6 +1509,7 @@ public static <T> Single<T> wrap(SingleSource<T> source) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Single<R> zip(final Iterable<? extends SingleSource<? extends T>> sources, Function<? super Object[], ? extends R> zipper) {
         ObjectHelper.requireNonNull(zipper, "zipper is null");
@@ -1504,6 +1541,7 @@ public static <T, R> Single<R> zip(final Iterable<? extends SingleSource<? exten
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, R> Single<R> zip(
@@ -1542,6 +1580,7 @@ public static <T1, T2, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, R> Single<R> zip(
@@ -1585,6 +1624,7 @@ public static <T1, T2, T3, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, R> Single<R> zip(
@@ -1632,6 +1672,7 @@ public static <T1, T2, T3, T4, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, T5, R> Single<R> zip(
@@ -1684,6 +1725,7 @@ public static <T1, T2, T3, T4, T5, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, T5, T6, R> Single<R> zip(
@@ -1740,6 +1782,7 @@ public static <T1, T2, T3, T4, T5, T6, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, T5, T6, T7, R> Single<R> zip(
@@ -1801,6 +1844,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Single<R> zip(
@@ -1866,6 +1910,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Single<R> zip(
      * @see <a href="http://reactivex.io/documentation/operators/zip.html">ReactiveX operators documentation: Zip</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Single<R> zip(
@@ -1918,6 +1963,7 @@ public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Single<R> zip(
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T, R> Single<R> zipArray(Function<? super Object[], ? extends R> zipper, SingleSource<? extends T>... sources) {
         ObjectHelper.requireNonNull(zipper, "zipper is null");
@@ -1942,6 +1988,7 @@ public static <T, R> Single<R> zipArray(Function<? super Object[], ? extends R>
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings("unchecked")
     public final Single<T> ambWith(SingleSource<? extends T> other) {
@@ -2048,6 +2095,7 @@ public final Single<T> cache() {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<U> cast(final Class<? extends U> clazz) {
         ObjectHelper.requireNonNull(clazz, "clazz is null");
@@ -2166,6 +2214,7 @@ public final Single<T> delay(final long time, final TimeUnit unit, final Schedul
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Single<T> delay(final long time, final TimeUnit unit, final Scheduler scheduler, boolean delayError) {
         ObjectHelper.requireNonNull(unit, "unit is null");
@@ -2188,6 +2237,7 @@ public final Single<T> delay(final long time, final TimeUnit unit, final Schedul
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> delaySubscription(CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2210,6 +2260,7 @@ public final Single<T> delaySubscription(CompletableSource other) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<T> delaySubscription(SingleSource<U> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2232,6 +2283,7 @@ public final <U> Single<T> delaySubscription(SingleSource<U> other) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<T> delaySubscription(ObservableSource<U> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2259,6 +2311,7 @@ public final <U> Single<T> delaySubscription(ObservableSource<U> other) {
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Single<T> delaySubscription(Publisher<U> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -2332,6 +2385,7 @@ public final Single<T> delaySubscription(long time, TimeUnit unit, Scheduler sch
      * @see #materialize()
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     @Experimental
     public final <R> Maybe<R> dematerialize(Function<? super T, Notification<R>> selector) {
@@ -2356,6 +2410,7 @@ public final <R> Maybe<R> dematerialize(Function<? super T, Notification<R>> sel
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
         ObjectHelper.requireNonNull(onAfterSuccess, "doAfterSuccess is null");
@@ -2384,6 +2439,7 @@ public final Single<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doAfterTerminate(Action onAfterTerminate) {
         ObjectHelper.requireNonNull(onAfterTerminate, "onAfterTerminate is null");
@@ -2410,6 +2466,7 @@ public final Single<T> doAfterTerminate(Action onAfterTerminate) {
      * @since 2.1
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doFinally(Action onFinally) {
         ObjectHelper.requireNonNull(onFinally, "onFinally is null");
@@ -2431,6 +2488,7 @@ public final Single<T> doFinally(Action onFinally) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doOnSubscribe(final Consumer<? super Disposable> onSubscribe) {
         ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
@@ -2452,6 +2510,7 @@ public final Single<T> doOnSubscribe(final Consumer<? super Disposable> onSubscr
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doOnSuccess(final Consumer<? super T> onSuccess) {
         ObjectHelper.requireNonNull(onSuccess, "onSuccess is null");
@@ -2470,6 +2529,7 @@ public final Single<T> doOnSuccess(final Consumer<? super T> onSuccess) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doOnEvent(final BiConsumer<? super T, ? super Throwable> onEvent) {
         ObjectHelper.requireNonNull(onEvent, "onEvent is null");
@@ -2491,6 +2551,7 @@ public final Single<T> doOnEvent(final BiConsumer<? super T, ? super Throwable>
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doOnError(final Consumer<? super Throwable> onError) {
         ObjectHelper.requireNonNull(onError, "onError is null");
@@ -2513,6 +2574,7 @@ public final Single<T> doOnError(final Consumer<? super Throwable> onError) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> doOnDispose(final Action onDispose) {
         ObjectHelper.requireNonNull(onDispose, "onDispose is null");
@@ -2537,6 +2599,7 @@ public final Single<T> doOnDispose(final Action onDispose) {
      * @see <a href="http://reactivex.io/documentation/operators/filter.html">ReactiveX operators documentation: Filter</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Maybe<T> filter(Predicate<? super T> predicate) {
         ObjectHelper.requireNonNull(predicate, "predicate is null");
@@ -2560,6 +2623,7 @@ public final Maybe<T> filter(Predicate<? super T> predicate) {
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> flatMap(Function<? super T, ? extends SingleSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2583,6 +2647,7 @@ public final <R> Single<R> flatMap(Function<? super T, ? extends SingleSource<?
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Maybe<R> flatMapMaybe(final Function<? super T, ? extends MaybeSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2611,6 +2676,7 @@ public final <R> Maybe<R> flatMapMaybe(final Function<? super T, ? extends Maybe
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publisher<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2639,6 +2705,7 @@ public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publ
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2663,6 +2730,7 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2686,6 +2754,7 @@ public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? e
      * @see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Observable<R> flatMapObservable(Function<? super T, ? extends ObservableSource<? extends R>> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2710,6 +2779,7 @@ public final <R> Observable<R> flatMapObservable(Function<? super T, ? extends O
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Completable flatMapCompletable(final Function<? super T, ? extends CompletableSource> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2879,6 +2949,7 @@ public final T blockingGet() {
      * @see #compose(SingleTransformer)
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> lift(final SingleOperator<? extends R, ? super T> lift) {
         ObjectHelper.requireNonNull(lift, "onLift is null");
@@ -2902,6 +2973,7 @@ public final <R> Single<R> lift(final SingleOperator<? extends R, ? super T> lif
      * @see <a href="http://reactivex.io/documentation/operators/map.html">ReactiveX operators documentation: Map</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Single<R> map(Function<? super T, ? extends R> mapper) {
         ObjectHelper.requireNonNull(mapper, "mapper is null");
@@ -2959,6 +3031,7 @@ public final Single<Boolean> contains(Object value) {
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<Boolean> contains(final Object value, final BiPredicate<Object, Object> comparer) {
         ObjectHelper.requireNonNull(value, "value is null");
@@ -3012,6 +3085,7 @@ public final Flowable<T> mergeWith(SingleSource<? extends T> other) {
      * @see #subscribeOn
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Single<T> observeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -3045,6 +3119,7 @@ public final Single<T> observeOn(final Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> onErrorReturn(final Function<Throwable, ? extends T> resumeFunction) {
         ObjectHelper.requireNonNull(resumeFunction, "resumeFunction is null");
@@ -3064,6 +3139,7 @@ public final Single<T> onErrorReturn(final Function<Throwable, ? extends T> resu
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> onErrorReturnItem(final T value) {
         ObjectHelper.requireNonNull(value, "value is null");
@@ -3098,6 +3174,7 @@ public final Single<T> onErrorReturnItem(final T value) {
      * @see <a href="http://reactivex.io/documentation/operators/catch.html">ReactiveX operators documentation: Catch</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> onErrorResumeNext(final Single<? extends T> resumeSingleInCaseOfError) {
         ObjectHelper.requireNonNull(resumeSingleInCaseOfError, "resumeSingleInCaseOfError is null");
@@ -3133,6 +3210,7 @@ public final Single<T> onErrorResumeNext(final Single<? extends T> resumeSingleI
      * @since .20
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> onErrorResumeNext(
             final Function<? super Throwable, ? extends SingleSource<? extends T>> resumeFunctionInCaseOfError) {
@@ -3419,6 +3497,7 @@ public final Disposable subscribe() {
      *             if {@code onCallback} is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final BiConsumer<? super T, ? super Throwable> onCallback) {
         ObjectHelper.requireNonNull(onCallback, "onCallback is null");
@@ -3472,6 +3551,7 @@ public final Disposable subscribe(Consumer<? super T> onSuccess) {
      *             if {@code onError} is null
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Consumer<? super T> onSuccess, final Consumer<? super Throwable> onError) {
         ObjectHelper.requireNonNull(onSuccess, "onSuccess is null");
@@ -3560,6 +3640,7 @@ public final <E extends SingleObserver<? super T>> E subscribeWith(E observer) {
      * @see #observeOn
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Single<T> subscribeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");
@@ -3584,6 +3665,7 @@ public final Single<T> subscribeOn(final Scheduler scheduler) {
      * @see <a href="http://reactivex.io/documentation/operators/takeuntil.html">ReactiveX operators documentation: TakeUntil</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Single<T> takeUntil(final CompletableSource other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3615,6 +3697,7 @@ public final Single<T> takeUntil(final CompletableSource other) {
      */
     @BackpressureSupport(BackpressureKind.FULL)
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <E> Single<T> takeUntil(final Publisher<E> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3640,6 +3723,7 @@ public final <E> Single<T> takeUntil(final Publisher<E> other) {
      * @see <a href="http://reactivex.io/documentation/operators/takeuntil.html">ReactiveX operators documentation: TakeUntil</a>
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <E> Single<T> takeUntil(final SingleSource<? extends E> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3699,6 +3783,7 @@ public final Single<T> timeout(long timeout, TimeUnit unit, Scheduler scheduler)
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Single<T> timeout(long timeout, TimeUnit unit, Scheduler scheduler, SingleSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3724,6 +3809,7 @@ public final Single<T> timeout(long timeout, TimeUnit unit, Scheduler scheduler,
      * @since 2.0
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.COMPUTATION)
     public final Single<T> timeout(long timeout, TimeUnit unit, SingleSource<? extends T> other) {
         ObjectHelper.requireNonNull(other, "other is null");
@@ -3902,6 +3988,7 @@ public final Observable<T> toObservable() {
      * @since 2.2
      */
     @CheckReturnValue
+    @NonNull
     @SchedulerSupport(SchedulerSupport.CUSTOM)
     public final Single<T> unsubscribeOn(final Scheduler scheduler) {
         ObjectHelper.requireNonNull(scheduler, "scheduler is null");