docs: public void greet(String name) {
      logger.info("Will try to greet " + name + " ...");
      HelloRequest request = HelloRequest.newBuilder().setName(name).build();
      HelloReply response;
  
      SpanBuilder spanBuilder =
          tracer.spanBuilder("client").setRecordEvents(true).setSampler(Samplers.alwaysSample());
      try (Scope scope = spanBuilder.startScopedSpan()) {
        tracer.getCurrentSpan().addAnnotation("Saying Hello to Server.");
        response = blockingStub.sayHello(request);
        tracer.getCurrentSpan().addAnnotation("Received response from Server.");
      } catch (StatusRuntimeException e) {
        tracer
            .getCurrentSpan()
            .setStatus(
                CanonicalCode.valueOf(e.getStatus().getCode().name())
                    .toStatus()
                    .withDescription(e.getMessage()));
        logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());
        return;
      }
      logger.info("Greeting: " + response.getMessage());
    }