default void addProductToProductSet(
        com.google.cloud.vision.v1.AddProductToProductSetRequest request,
        io.grpc.stub.StreamObserver<com.google.protobuf.Empty> responseObserver) {
      io.grpc.stub.ServerCalls.asyncUnimplementedUnaryCall(
          getAddProductToProductSetMethod(), responseObserver);
    }
<pre>
Adds a Product to the specified ProductSet. If the Product is already
present, no change is made.
One Product can be added to at most 100 ProductSets.
Possible errors:
* Returns NOT_FOUND if the Product or the ProductSet doesn't exist.
</pre>
java-vision/grpc-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/ProductSearchGrpc.java