How to use

nullToSelf

method

in

com.google.api.gax.grpc.GrpcCallContext

 private ApiCallContext contextWithParamsEncoder(RequestT request, ApiCallContext inputContext) {
  return GrpcCallContext.createDefault()
    .nullToSelf(inputContext)
    .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));
 }
}

@Override
public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
 GrpcCallContext context = GrpcCallContext.createDefault().nullToSelf(inputContext);
 ApiFuture<ResponseT> innerCallFuture = callable.futureCall(request, context);
 ExceptionTransformingFuture transformingFuture =
   new ExceptionTransformingFuture(innerCallFuture);
 ApiFutures.addCallback(innerCallFuture, transformingFuture, directExecutor());
 return transformingFuture;
}

@Override
public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
 GrpcCallContext context = GrpcCallContext.createDefault().nullToSelf(inputContext);
 ApiFuture<ResponseT> innerCallFuture = callable.futureCall(request, context);
 ExceptionTransformingFuture transformingFuture =
   new ExceptionTransformingFuture(innerCallFuture);
 ApiFutures.addCallback(innerCallFuture, transformingFuture, directExecutor());
 return transformingFuture;
}

 private ApiCallContext contextWithParamsEncoder(RequestT request, ApiCallContext inputContext) {
  return GrpcCallContext.createDefault()
    .nullToSelf(inputContext)
    .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));
 }
}

 @Override
 public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
  GrpcCallContext newCallContext =
    GrpcCallContext.createDefault()
      .nullToSelf(inputContext)
      .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));

  return callable.futureCall(request, newCallContext);
 }
}

 @Override
 public ApiFuture<ResponseT> futureCall(RequestT request, ApiCallContext inputContext) {
  GrpcCallContext newCallContext =
    GrpcCallContext.createDefault()
      .nullToSelf(inputContext)
      .withRequestParamsDynamicHeaderOption(paramsEncoder.encode(request));

  return callable.futureCall(request, newCallContext);
 }
}

@Test
public void testNullToSelfWrongType() {
 thrown.expect(IllegalArgumentException.class);
 GrpcCallContext.createDefault().nullToSelf(FakeCallContext.createDefault());
}