class LoggingClientInterceptor implements ClientInterceptor {

  private static final Logger log = LoggerFactory.getLogger(LoggingClientInterceptor.class);

  @Override
  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method,
      CallOptions callOptions, Channel next) {
    return new SimpleForwardingClientCall<ReqT, RespT>(next.newCall(method, callOptions)) {
      @Override
      public void start(Listener<RespT> responseListener, Metadata headers) {
        log.info("grpc request; method: {}, attributes: {}", method.getFullMethodName(),
            getAttributes());

        super.start(responseListener, headers);
      }
    };
  }
}