diff --git a/src/main/resources/com/google/api/codegen/java/main.snip b/src/main/resources/com/google/api/codegen/java/main.snip
index e8ec777819..311cc20f33 100644
--- a/src/main/resources/com/google/api/codegen/java/main.snip
+++ b/src/main/resources/com/google/api/codegen/java/main.snip
@@ -357,7 +357,7 @@
   // AUTO-GENERATED DOCUMENTATION AND METHOD
   /**
   @join commentLine : apiMethodDoc.mainDocLines
-    {@""} * {@commentLine} 
+    {@""} * {@commentLine}
   @end
    *
    * Sample code:
@@ -368,7 +368,7 @@
    * </code></pre>
   @if apiMethodDoc.paramDocs
     {@""} *
-    @join doc : apiMethodDoc.paramDocs 
+    @join doc : apiMethodDoc.paramDocs
       {@paramDoc(doc)}
     @end
   @end
@@ -406,5 +406,13 @@
 @end
 
 @private pathTemplateCheckLine(pathTemplateCheck)
-  {@pathTemplateCheck.pathTemplateName}.validate({@pathTemplateCheck.paramName}, "{@pathTemplateCheck.validationMessageContext}");
+  @if pathTemplateCheck.allowEmptyString
+    if (!{@pathTemplateCheck.paramName}.isEmpty()) {
+      {@pathTemplateCheck.pathTemplateName}.validate({@pathTemplateCheck.paramName}, \
+        "{@pathTemplateCheck.validationMessageContext}");
+    }
+  @else
+    {@pathTemplateCheck.pathTemplateName}.validate({@pathTemplateCheck.paramName}, \
+      "{@pathTemplateCheck.validationMessageContext}");
+  @end
 @end
diff --git a/src/main/resources/com/google/api/codegen/java/mock_service.snip b/src/main/resources/com/google/api/codegen/java/mock_service.snip
index c53170de95..9bb43d7f1f 100644
--- a/src/main/resources/com/google/api/codegen/java/mock_service.snip
+++ b/src/main/resources/com/google/api/codegen/java/mock_service.snip
@@ -22,6 +22,11 @@
       return serviceImpl.getRequests();
     }
 
+    @@Override
+    public void setResponses(List<GeneratedMessage> responses) {
+      serviceImpl.setResponses(responses);
+    }
+
     @@Override
     public ServerServiceDefinition getServiceDefinition() {
       return {@mockService.grpcContainerName}.bindService(serviceImpl);
diff --git a/src/main/resources/com/google/api/codegen/java/mock_service_impl.snip b/src/main/resources/com/google/api/codegen/java/mock_service_impl.snip
index 0785a078b2..0e9ae65266 100644
--- a/src/main/resources/com/google/api/codegen/java/mock_service_impl.snip
+++ b/src/main/resources/com/google/api/codegen/java/mock_service_impl.snip
@@ -11,42 +11,41 @@
 
   @@javax.annotation.Generated("by GAPIC")
   public class {@mockServiceImpl.name} implements {@mockServiceImpl.grpcClassName}  {
-     private ArrayList<GeneratedMessage> requests;
+    private ArrayList<GeneratedMessage> requests;
+    private Queue<GeneratedMessage> responses;
 
-     public {@mockServiceImpl.name}() {
-       requests = new ArrayList<>();
-     }
+    public {@mockServiceImpl.name}() {
+      requests = new ArrayList<>();
+      responses = new LinkedList<>();
+    }
 
-     public List<GeneratedMessage> getRequests() {
-       return requests;
-     }
+    public List<GeneratedMessage> getRequests() {
+      return requests;
+    }
 
-     public void reset() {
-       requests = new ArrayList<>();
-     }
+    public void setResponses(List<GeneratedMessage> responses) {
+      this.responses = Lists.newLinkedList(responses);
+    }
+
+    public void reset() {
+      requests = new ArrayList<>();
+      responses = new LinkedList<>();
+    }
 
-     @join method : mockServiceImpl.grpcMethods
-      {@grpcMethod(method)}
+    @join method : mockServiceImpl.grpcMethods
+     {@grpcMethod(method)}
 
-     @end
+    @end
   }
 @end
 
 @private grpcMethod(method)
   @@Override
-  @if method.isStreaming
-    public StreamObserver<{@method.requestTypeName}> {@method.name}(
-        StreamObserver<{@method.responseTypeName}> responseObserver) {
-      System.err.println("Streaming method is not supported.");
-      return null;
-    }
-  @else
-    public void {@method.name}({@method.requestTypeName} request,
-      StreamObserver<{@method.responseTypeName}> responseObserver) {
-      {@method.responseTypeName} response = ({@method.responseTypeName}) responses.remove();
-      requests.add(request);
-      responseObserver.onNext(response);
-      responseObserver.onCompleted();
-    }
-  @end
+  public void {@method.name}({@method.requestTypeName} request,
+    StreamObserver<{@method.responseTypeName}> responseObserver) {
+    {@method.responseTypeName} response = ({@method.responseTypeName}) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
 @end
diff --git a/src/main/resources/com/google/api/codegen/java/test.snip b/src/main/resources/com/google/api/codegen/java/test.snip
index e44f4a44b9..80425dfba9 100644
--- a/src/main/resources/com/google/api/codegen/java/test.snip
+++ b/src/main/resources/com/google/api/codegen/java/test.snip
@@ -52,31 +52,48 @@
   @@Test
   @@SuppressWarnings("all")
   public void {@test.name}() {
+    {@setResponse(test.mockResponse)}
+
     {@initCode(test.initCode)}
     {@methodCall(test)}
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    {@test.requestTypeName} request = ({@test.requestTypeName})requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    {@test.requestTypeName} actualRequest = ({@test.requestTypeName})actualRequests.get(0);
 
     @join assert : test.asserts
-      Assert.assertEquals(request.{@assert.actualValueGetter}(), {@assert.expectedValueIdentifier});
+      Assert.assertEquals(actualRequest.{@assert.actualValueGetter}(), {@assert.expectedValueIdentifier});
     @end
   }
 @end
 
+@private setResponse(response)
+  {@initCode(response.initCode)}
+  List<GeneratedMessage> expectedResponses = new ArrayList<>();
+  expectedResponses.add(expectedResponse);
+  serviceHelper.getService().setResponses(expectedResponses);
+@end
+
 @private methodCall(test)
   @switch test.methodType
   @case "PagedFlattenedMethod"
-    PageAccessor<{@test.resourceTypeName}> response = api.{@test.surfaceMethodName}(\
+    PageAccessor<{@test.resourceTypeName}> pageAccessor = api.{@test.surfaceMethodName}(\
       {@sampleMethodCallArgList(test.initCode.fieldSettings)});
 
     // PageAccessor will not make actual request until it is being used.
     // Add all the pages here in order to make grpc requests.
-    List<{@test.resourceTypeName}> resources = Lists.newArrayList(response.getPageValues());
+    List<{@test.resourceTypeName}> resources = Lists.newArrayList(pageAccessor.getPageValues());
+    Assert.assertEquals(0, resources.size());
   @case "FlattenedMethod"
-    api.{@test.surfaceMethodName}(\
-      {@sampleMethodCallArgList(test.initCode.fieldSettings)});
+    @if test.hasReturnValue
+      {@test.responseTypeName} actualResponse =
+          api.{@test.surfaceMethodName}(\
+          {@sampleMethodCallArgList(test.initCode.fieldSettings)});
+      Assert.assertEquals(expectedResponse, actualResponse);
+    @else
+      api.{@test.surfaceMethodName}(\
+            {@sampleMethodCallArgList(test.initCode.fieldSettings)});
+    @end
   @default
     $unhandledCase: {@test.type}$
   @end
diff --git a/src/test/java/com/google/api/codegen/testdata/java_mock_service_impl_library.baseline b/src/test/java/com/google/api/codegen/testdata/java_mock_service_impl_library.baseline
index c4f07836e4..6555f980d2 100644
--- a/src/test/java/com/google/api/codegen/testdata/java_mock_service_impl_library.baseline
+++ b/src/test/java/com/google/api/codegen/testdata/java_mock_service_impl_library.baseline
@@ -51,178 +51,187 @@ import java.util.Queue;
 
 @javax.annotation.Generated("by GAPIC")
 public class MockLibraryServiceImpl implements LibraryService  {
-   private ArrayList<GeneratedMessage> requests;
-
-   public MockLibraryServiceImpl() {
-     requests = new ArrayList<>();
-   }
-
-   public List<GeneratedMessage> getRequests() {
-     return requests;
-   }
-
-   public void reset() {
-     requests = new ArrayList<>();
-   }
-
-   @Override
-   public void createShelf(CreateShelfRequest request,
-     StreamObserver<Shelf> responseObserver) {
-     Shelf response = (Shelf) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void getShelf(GetShelfRequest request,
-     StreamObserver<Shelf> responseObserver) {
-     Shelf response = (Shelf) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void listShelves(ListShelvesRequest request,
-     StreamObserver<ListShelvesResponse> responseObserver) {
-     ListShelvesResponse response = (ListShelvesResponse) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void deleteShelf(DeleteShelfRequest request,
-     StreamObserver<Empty> responseObserver) {
-     Empty response = (Empty) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void mergeShelves(MergeShelvesRequest request,
-     StreamObserver<Shelf> responseObserver) {
-     Shelf response = (Shelf) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void createBook(CreateBookRequest request,
-     StreamObserver<Book> responseObserver) {
-     Book response = (Book) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void publishSeries(PublishSeriesRequest request,
-     StreamObserver<PublishSeriesResponse> responseObserver) {
-     PublishSeriesResponse response = (PublishSeriesResponse) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void getBook(GetBookRequest request,
-     StreamObserver<Book> responseObserver) {
-     Book response = (Book) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void listBooks(ListBooksRequest request,
-     StreamObserver<ListBooksResponse> responseObserver) {
-     ListBooksResponse response = (ListBooksResponse) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void deleteBook(DeleteBookRequest request,
-     StreamObserver<Empty> responseObserver) {
-     Empty response = (Empty) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void updateBook(UpdateBookRequest request,
-     StreamObserver<Book> responseObserver) {
-     Book response = (Book) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void moveBook(MoveBookRequest request,
-     StreamObserver<Book> responseObserver) {
-     Book response = (Book) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void listStrings(ListStringsRequest request,
-     StreamObserver<ListStringsResponse> responseObserver) {
-     ListStringsResponse response = (ListStringsResponse) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void addComments(AddCommentsRequest request,
-     StreamObserver<Empty> responseObserver) {
-     Empty response = (Empty) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void getBookFromArchive(GetBookFromArchiveRequest request,
-     StreamObserver<Book> responseObserver) {
-     Book response = (Book) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public void updateBookIndex(UpdateBookIndexRequest request,
-     StreamObserver<Empty> responseObserver) {
-     Empty response = (Empty) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
-
-   @Override
-   public StreamObserver<ListShelvesRequest> streamShelves(
-       StreamObserver<ListShelvesResponse> responseObserver) {
-     System.err.println("Streaming method is not supported.");
-     return null;
-   }
-
-   @Override
-   public void addTag(AddTagRequest request,
-     StreamObserver<AddTagResponse> responseObserver) {
-     AddTagResponse response = (AddTagResponse) responses.remove();
-     requests.add(request);
-     responseObserver.onNext(response);
-     responseObserver.onCompleted();
-   }
+  private ArrayList<GeneratedMessage> requests;
+  private Queue<GeneratedMessage> responses;
+
+  public MockLibraryServiceImpl() {
+    requests = new ArrayList<>();
+    responses = new LinkedList<>();
+  }
+
+  public List<GeneratedMessage> getRequests() {
+    return requests;
+  }
+
+  public void setResponses(List<GeneratedMessage> responses) {
+    this.responses = Lists.newLinkedList(responses);
+  }
+
+  public void reset() {
+    requests = new ArrayList<>();
+    responses = new LinkedList<>();
+  }
+
+  @Override
+  public void createShelf(CreateShelfRequest request,
+    StreamObserver<Shelf> responseObserver) {
+    Shelf response = (Shelf) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void getShelf(GetShelfRequest request,
+    StreamObserver<Shelf> responseObserver) {
+    Shelf response = (Shelf) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void listShelves(ListShelvesRequest request,
+    StreamObserver<ListShelvesResponse> responseObserver) {
+    ListShelvesResponse response = (ListShelvesResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void deleteShelf(DeleteShelfRequest request,
+    StreamObserver<Empty> responseObserver) {
+    Empty response = (Empty) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void mergeShelves(MergeShelvesRequest request,
+    StreamObserver<Shelf> responseObserver) {
+    Shelf response = (Shelf) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void createBook(CreateBookRequest request,
+    StreamObserver<Book> responseObserver) {
+    Book response = (Book) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void publishSeries(PublishSeriesRequest request,
+    StreamObserver<PublishSeriesResponse> responseObserver) {
+    PublishSeriesResponse response = (PublishSeriesResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void getBook(GetBookRequest request,
+    StreamObserver<Book> responseObserver) {
+    Book response = (Book) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void listBooks(ListBooksRequest request,
+    StreamObserver<ListBooksResponse> responseObserver) {
+    ListBooksResponse response = (ListBooksResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void deleteBook(DeleteBookRequest request,
+    StreamObserver<Empty> responseObserver) {
+    Empty response = (Empty) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void updateBook(UpdateBookRequest request,
+    StreamObserver<Book> responseObserver) {
+    Book response = (Book) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void moveBook(MoveBookRequest request,
+    StreamObserver<Book> responseObserver) {
+    Book response = (Book) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void listStrings(ListStringsRequest request,
+    StreamObserver<ListStringsResponse> responseObserver) {
+    ListStringsResponse response = (ListStringsResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void addComments(AddCommentsRequest request,
+    StreamObserver<Empty> responseObserver) {
+    Empty response = (Empty) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void getBookFromArchive(GetBookFromArchiveRequest request,
+    StreamObserver<Book> responseObserver) {
+    Book response = (Book) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void updateBookIndex(UpdateBookIndexRequest request,
+    StreamObserver<Empty> responseObserver) {
+    Empty response = (Empty) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void streamShelves(ListShelvesRequest request,
+    StreamObserver<ListShelvesResponse> responseObserver) {
+    ListShelvesResponse response = (ListShelvesResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
+
+  @Override
+  public void addTag(AddTagRequest request,
+    StreamObserver<AddTagResponse> responseObserver) {
+    AddTagResponse response = (AddTagResponse) responses.remove();
+    requests.add(request);
+    responseObserver.onNext(response);
+    responseObserver.onCompleted();
+  }
 
 }
diff --git a/src/test/java/com/google/api/codegen/testdata/java_mock_service_library.baseline b/src/test/java/com/google/api/codegen/testdata/java_mock_service_library.baseline
index b711297e1a..b0b2052e37 100644
--- a/src/test/java/com/google/api/codegen/testdata/java_mock_service_library.baseline
+++ b/src/test/java/com/google/api/codegen/testdata/java_mock_service_library.baseline
@@ -34,6 +34,11 @@ public class MockLibraryService implements MockGrpcService  {
     return serviceImpl.getRequests();
   }
 
+  @Override
+  public void setResponses(List<GeneratedMessage> responses) {
+    serviceImpl.setResponses(responses);
+  }
+
   @Override
   public ServerServiceDefinition getServiceDefinition() {
     return LibraryServiceGrpc.bindService(serviceImpl);
diff --git a/src/test/java/com/google/api/codegen/testdata/java_test_library.baseline b/src/test/java/com/google/api/codegen/testdata/java_test_library.baseline
index 881ba1dbb5..2ed3f28d56 100644
--- a/src/test/java/com/google/api/codegen/testdata/java_test_library.baseline
+++ b/src/test/java/com/google/api/codegen/testdata/java_test_library.baseline
@@ -94,250 +94,377 @@ public class LibraryServiceTest {
   @Test
   @SuppressWarnings("all")
   public void createShelfTest() {
+    Shelf expectedResponse = Shelf.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     Shelf shelf = Shelf.newBuilder().build();
-    api.createShelf(shelf);
+    Shelf actualResponse =
+        api.createShelf(shelf);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    CreateShelfRequest request = (CreateShelfRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    CreateShelfRequest actualRequest = (CreateShelfRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getShelf(), shelf);
+    Assert.assertEquals(actualRequest.getShelf(), shelf);
   }
 
   @Test
   @SuppressWarnings("all")
   public void getShelfTest() {
+    Shelf expectedResponse = Shelf.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
-    api.getShelf(formattedName);
+    Shelf actualResponse =
+        api.getShelf(formattedName);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    GetShelfRequest request = (GetShelfRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    GetShelfRequest actualRequest = (GetShelfRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void getShelfTest2() {
+    Shelf expectedResponse = Shelf.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     SomeMessage message = SomeMessage.newBuilder().build();
-    api.getShelf(formattedName, message);
+    Shelf actualResponse =
+        api.getShelf(formattedName, message);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    GetShelfRequest request = (GetShelfRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    GetShelfRequest actualRequest = (GetShelfRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getMessage(), message);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getMessage(), message);
   }
 
   @Test
   @SuppressWarnings("all")
   public void getShelfTest3() {
+    Shelf expectedResponse = Shelf.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     SomeMessage message = SomeMessage.newBuilder().build();
     com.google.example.library.v1.StringBuilder stringBuilder = com.google.example.library.v1.StringBuilder.newBuilder().build();
-    api.getShelf(formattedName, message, stringBuilder);
+    Shelf actualResponse =
+        api.getShelf(formattedName, message, stringBuilder);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    GetShelfRequest request = (GetShelfRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    GetShelfRequest actualRequest = (GetShelfRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getMessage(), message);
-    Assert.assertEquals(request.getStringBuilder(), stringBuilder);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getMessage(), message);
+    Assert.assertEquals(actualRequest.getStringBuilder(), stringBuilder);
   }
 
   @Test
   @SuppressWarnings("all")
   public void listShelvesTest() {
+    ListShelvesResponse expectedResponse = ListShelvesResponse.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
 
-    PageAccessor<Shelf> response = api.listShelves();
+
+    PageAccessor<Shelf> pageAccessor = api.listShelves();
 
     // PageAccessor will not make actual request until it is being used.
     // Add all the pages here in order to make grpc requests.
-    List<Shelf> resources = Lists.newArrayList(response.getPageValues());
+    List<Shelf> resources = Lists.newArrayList(pageAccessor.getPageValues());
+    Assert.assertEquals(0, resources.size());
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    ListShelvesRequest request = (ListShelvesRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    ListShelvesRequest actualRequest = (ListShelvesRequest)actualRequests.get(0);
 
   }
 
   @Test
   @SuppressWarnings("all")
   public void deleteShelfTest() {
+    Empty expectedResponse = Empty.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     api.deleteShelf(formattedName);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    DeleteShelfRequest request = (DeleteShelfRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    DeleteShelfRequest actualRequest = (DeleteShelfRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void mergeShelvesTest() {
+    Shelf expectedResponse = Shelf.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     String formattedOtherShelfName = LibraryServiceApi.formatShelfName("[SHELF]");
-    api.mergeShelves(formattedName, formattedOtherShelfName);
+    Shelf actualResponse =
+        api.mergeShelves(formattedName, formattedOtherShelfName);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    MergeShelvesRequest request = (MergeShelvesRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    MergeShelvesRequest actualRequest = (MergeShelvesRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getOtherShelfName(), formattedOtherShelfName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getOtherShelfName(), formattedOtherShelfName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void createBookTest() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     Book book = Book.newBuilder().build();
-    api.createBook(formattedName, book);
+    Book actualResponse =
+        api.createBook(formattedName, book);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    CreateBookRequest request = (CreateBookRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    CreateBookRequest actualRequest = (CreateBookRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getBook(), book);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getBook(), book);
   }
 
   @Test
   @SuppressWarnings("all")
   public void publishSeriesTest() {
+    PublishSeriesResponse expectedResponse = PublishSeriesResponse.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     Shelf shelf = Shelf.newBuilder().build();
     List<Book> books = new ArrayList<>();
     int edition = 0;
-    api.publishSeries(shelf, books, edition);
+    PublishSeriesResponse actualResponse =
+        api.publishSeries(shelf, books, edition);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    PublishSeriesRequest request = (PublishSeriesRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    PublishSeriesRequest actualRequest = (PublishSeriesRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getShelf(), shelf);
-    Assert.assertEquals(request.getBooksList(), books);
-    Assert.assertEquals(request.getEdition(), edition);
+    Assert.assertEquals(actualRequest.getShelf(), shelf);
+    Assert.assertEquals(actualRequest.getBooksList(), books);
+    Assert.assertEquals(actualRequest.getEdition(), edition);
   }
 
   @Test
   @SuppressWarnings("all")
   public void getBookTest() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
-    api.getBook(formattedName);
+    Book actualResponse =
+        api.getBook(formattedName);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    GetBookRequest request = (GetBookRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    GetBookRequest actualRequest = (GetBookRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void listBooksTest() {
+    ListBooksResponse expectedResponse = ListBooksResponse.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatShelfName("[SHELF]");
     String filter = "";
-    PageAccessor<Book> response = api.listBooks(formattedName, filter);
+    PageAccessor<Book> pageAccessor = api.listBooks(formattedName, filter);
 
     // PageAccessor will not make actual request until it is being used.
     // Add all the pages here in order to make grpc requests.
-    List<Book> resources = Lists.newArrayList(response.getPageValues());
+    List<Book> resources = Lists.newArrayList(pageAccessor.getPageValues());
+    Assert.assertEquals(0, resources.size());
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    ListBooksRequest request = (ListBooksRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    ListBooksRequest actualRequest = (ListBooksRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getFilter(), filter);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getFilter(), filter);
   }
 
   @Test
   @SuppressWarnings("all")
   public void deleteBookTest() {
+    Empty expectedResponse = Empty.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     api.deleteBook(formattedName);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    DeleteBookRequest request = (DeleteBookRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    DeleteBookRequest actualRequest = (DeleteBookRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void updateBookTest() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     Book book = Book.newBuilder().build();
-    api.updateBook(formattedName, book);
+    Book actualResponse =
+        api.updateBook(formattedName, book);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    UpdateBookRequest request = (UpdateBookRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    UpdateBookRequest actualRequest = (UpdateBookRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getBook(), book);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getBook(), book);
   }
 
   @Test
   @SuppressWarnings("all")
   public void updateBookTest2() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     Book book = Book.newBuilder().build();
     FieldMask updateMask = FieldMask.newBuilder().build();
     com.google.example.library.v1.FieldMask physicalMask = com.google.example.library.v1.FieldMask.newBuilder().build();
-    api.updateBook(formattedName, book, updateMask, physicalMask);
-
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    UpdateBookRequest request = (UpdateBookRequest)requests.get(0);
-
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getBook(), book);
-    Assert.assertEquals(request.getUpdateMask(), updateMask);
-    Assert.assertEquals(request.getPhysicalMask(), physicalMask);
+    Book actualResponse =
+        api.updateBook(formattedName, book, updateMask, physicalMask);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    UpdateBookRequest actualRequest = (UpdateBookRequest)actualRequests.get(0);
+
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getBook(), book);
+    Assert.assertEquals(actualRequest.getUpdateMask(), updateMask);
+    Assert.assertEquals(actualRequest.getPhysicalMask(), physicalMask);
   }
 
   @Test
   @SuppressWarnings("all")
   public void moveBookTest() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     String formattedOtherShelfName = LibraryServiceApi.formatShelfName("[SHELF]");
-    api.moveBook(formattedName, formattedOtherShelfName);
+    Book actualResponse =
+        api.moveBook(formattedName, formattedOtherShelfName);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    MoveBookRequest request = (MoveBookRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    MoveBookRequest actualRequest = (MoveBookRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getOtherShelfName(), formattedOtherShelfName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getOtherShelfName(), formattedOtherShelfName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void listStringsTest() {
+    ListStringsResponse expectedResponse = ListStringsResponse.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
 
-    PageAccessor<String> response = api.listStrings();
+    PageAccessor<String> pageAccessor = api.listStrings();
 
     // PageAccessor will not make actual request until it is being used.
     // Add all the pages here in order to make grpc requests.
-    List<String> resources = Lists.newArrayList(response.getPageValues());
+    List<String> resources = Lists.newArrayList(pageAccessor.getPageValues());
+    Assert.assertEquals(0, resources.size());
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    ListStringsRequest request = (ListStringsRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    ListStringsRequest actualRequest = (ListStringsRequest)actualRequests.get(0);
 
   }
 
   @Test
   @SuppressWarnings("all")
   public void addCommentsTest() {
+    Empty expectedResponse = Empty.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     ByteString comment = ByteString.copyFromUtf8("");
     Stage stage = Stage.UNSET;
@@ -348,30 +475,44 @@ public class LibraryServiceTest {
     List<Comment> comments = Arrays.asList(commentsElement);
     api.addComments(formattedName, comments);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    AddCommentsRequest request = (AddCommentsRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    AddCommentsRequest actualRequest = (AddCommentsRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getCommentsList(), comments);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getCommentsList(), comments);
   }
 
   @Test
   @SuppressWarnings("all")
   public void getBookFromArchiveTest() {
+    Book expectedResponse = Book.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatArchivedBookName("[ARCHIVE_PATH]", "[BOOK]");
-    api.getBookFromArchive(formattedName);
+    Book actualResponse =
+        api.getBookFromArchive(formattedName);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    GetBookFromArchiveRequest request = (GetBookFromArchiveRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    GetBookFromArchiveRequest actualRequest = (GetBookFromArchiveRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
   }
 
   @Test
   @SuppressWarnings("all")
   public void updateBookIndexTest() {
+    Empty expectedResponse = Empty.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedName = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     String indexName = "default index";
     String indexMapItem = "";
@@ -379,28 +520,36 @@ public class LibraryServiceTest {
     indexMap.put("default_key", indexMapItem);
     api.updateBookIndex(formattedName, indexName, indexMap);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    UpdateBookIndexRequest request = (UpdateBookIndexRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    UpdateBookIndexRequest actualRequest = (UpdateBookIndexRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getName(), formattedName);
-    Assert.assertEquals(request.getIndexName(), indexName);
-    Assert.assertEquals(request.getIndexMap(), indexMap);
+    Assert.assertEquals(actualRequest.getName(), formattedName);
+    Assert.assertEquals(actualRequest.getIndexName(), indexName);
+    Assert.assertEquals(actualRequest.getIndexMap(), indexMap);
   }
 
   @Test
   @SuppressWarnings("all")
   public void addTagTest() {
+    AddTagResponse expectedResponse = AddTagResponse.newBuilder()
+      .build();
+    List<GeneratedMessage> expectedResponses = new ArrayList<>();
+    expectedResponses.add(expectedResponse);
+    serviceHelper.getService().setResponses(expectedResponses);
+
     String formattedResource = LibraryServiceApi.formatBookName("[SHELF]", "[BOOK]");
     String tag = "";
-    api.addTag(formattedResource, tag);
+    AddTagResponse actualResponse =
+        api.addTag(formattedResource, tag);
+    Assert.assertEquals(expectedResponse, actualResponse);
 
-    List<GeneratedMessage> requests = serviceHelper.getService().getRequests();
-    Assert.assertEquals(1, requests.size());
-    AddTagRequest request = (AddTagRequest)requests.get(0);
+    List<GeneratedMessage> actualRequests = serviceHelper.getService().getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    AddTagRequest actualRequest = (AddTagRequest)actualRequests.get(0);
 
-    Assert.assertEquals(request.getResource(), formattedResource);
-    Assert.assertEquals(request.getTag(), tag);
+    Assert.assertEquals(actualRequest.getResource(), formattedResource);
+    Assert.assertEquals(actualRequest.getTag(), tag);
   }
 
 }