@Override
                                public void onClose(final Status status, final Metadata trailers) {
                                    super.onClose(status, trailers);
                                    thatCounter.countDown();
                                }
A testing client interceptor, that allows awaiting the completion of the client call that is otherwise closed
asynchronously.

@return A testing client interceptor bean.
tests/src/test/java/net/devh/boot/grpc/test/config/AwaitableServerClientCallConfiguration.java