问grpc客户端代码在cpp/c++中元数据x- API -key/x-goog-api-key不工作，给我语音API的中断管道

EN

int main(int argc, char** argv) {
  // Create a Speech Stub connected to the speech service.
  //auto creds = grpc::GoogleDefaultCredentials();
  /*auto channel = grpc::CreateChannel("speech.googleapis.com", creds); */
  auto channel = grpc::CreateChannel("speech.googleapis.com", grpc::InsecureChannelCredentials());
  if (channel == nullptr)
   {
        std::cout << "could not allocate channel" <<std::endl;
        return -1;
  }
std::unique_ptr<Speech::Stub> speech(Speech::NewStub(channel));
  // Parse command line arguments.
  StreamingRecognizeRequest request;
  auto* streaming_config = request.mutable_streaming_config();
  char* file_path =
      ParseArguments(argc, argv, streaming_config->mutable_config());
  if (nullptr == file_path) {
    std::cerr << kUsage;
    return -1;
  }
  auto start = std::chrono::system_clock::now();
  std::time_t start_time = std::chrono::system_clock::to_time_t(start);
  std::cout << "time start " << std::ctime(&start_time) << std::endl;

  // Begin a stream.
  grpc::ClientContext context;

  context.AddMetadata("x-api-key", "AIzaSxxxxxxxxxxxxxxxxxxxxxxxxxx");

  auto streamer = speech->StreamingRecognize(&context);
  // Write the first request, containing the config only.
  streaming_config->set_interim_results(true);
  streamer->Write(request);
  // The microphone thread writes the audio content.
  std::thread microphone_thread(&MicrophoneThreadMain, streamer.get(),
                                file_path);
  // Read responses.
  StreamingRecognizeResponse response;
  while (streamer->Read(&response)) {  // Returns false when no more to read.
    // Dump the transcript of all the results.
    for (int r = 0; r < response.results_size(); ++r) {
      const auto& result = response.results(r);
      std::cout << "Result stability: " << result.stability() << std::endl;
      for (int a = 0; a < result.alternatives_size(); ++a) {
        const auto& alternative = result.alternatives(a);
        std::cout << alternative.confidence() << "\t"
                  << alternative.transcript() << std::endl;
      }
    }
  }