public Span handleReceive(HttpServerRequest request) {
    Span span = nextSpan(defaultExtractor.extract(request), request);
    return handleStart(request, span);
  }
@Test void handleReceive_traceIdSamplerSpecialCased() {
    Sampler sampler = mock(Sampler.class);

    init(httpTracingBuilder(tracingBuilder().sampler(sampler))
      .serverSampler(SamplerFunctions.deferDecision()));

    assertThat(handler.handleReceive(request).isNoop()).isTrue();

    verify(sampler).isSampled(anyLong());
  }