static FinishSpan create(TracingFilter filter, DubboRequest request, Result result, Span span) {
    if (request instanceof DubboClientRequest) {
      return new FinishClientSpan(
        span, result, filter.clientHandler, (DubboClientRequest) request);
    }
    return new FinishServerSpan(span, result, filter.serverHandler, (DubboServerRequest) request);
  }
@Test void create_null_result_value_and_error_DubboClientRequest() {
    Span span = tracing.tracer().nextSpan().kind(CLIENT).start();

    FinishSpan.create(filter, clientRequest, mock(Result.class), span)
        .accept(null, null);

    testSpanHandler.takeRemoteSpan(CLIENT);
  }