Fix pagings with headers

azure-client-runtime/src/main/java/com/microsoft/azure/AzureServiceCall.java

@@ -12,6 +12,7 @@
 
 import java.util.List;
 
+import com.microsoft.rest.ServiceResponseWithHeaders;
 import rx.Observable;
 import rx.Subscriber;
 import rx.functions.Func1;
@@ -45,6 +46,26 @@ public static <E> ServiceCall<List<E>> create(Observable<ServiceResponse<Page<E>
         return serviceCall;
     }
 
+    public static <E, V> ServiceCall<List<E>> createWithHeaders(Observable<ServiceResponseWithHeaders<Page<E>, V>> first, final Func1<String, Observable<ServiceResponseWithHeaders<Page<E>, V>>> next, final ListOperationCallback<E> callback) {
+        final AzureServiceCall<List<E>> serviceCall = new AzureServiceCall<>();
+        final PagingSubscriber<E> subscriber = new PagingSubscriber<>(serviceCall, new Func1<String, Observable<ServiceResponse<Page<E>>>>() {
+            @Override
+            public Observable<ServiceResponse<Page<E>>> call(String s) {
+                return next.call(s)
+                        .map(new Func1<ServiceResponseWithHeaders<Page<E>, V>, ServiceResponse<Page<E>>>() {
+                            @Override
+                            public ServiceResponse<Page<E>> call(ServiceResponseWithHeaders<Page<E>, V> pageVServiceResponseWithHeaders) {
+                                return pageVServiceResponseWithHeaders;
+                            }
+                        });
+            }
+        }, callback);
+        serviceCall.setSubscription(first
+                .single()
+                .subscribe(subscriber));
+        return serviceCall;
+    }
+
     /**
      * The subscriber that handles user callback and automatically subscribes to the next page.
      *