@Override
                        public void sendResponse(final Object responseObj) {
                            try {
                                responseObserver.onNext((Message) responseObj);
                                responseObserver.onCompleted();
                            } catch (final Throwable t) {
                                LOG.warn("[GRPC] failed to send response.", t);
                            }
                        }
GRPC RPC server implement.

@author nicholas.jxf
@author jiachun.fjc
jraft-extension/rpc-grpc-impl/src/main/java/com/alipay/sofa/jraft/rpc/impl/GrpcServer.java