@Test
public void testLocalSpan() throws Exception {

    {
        router.route("/localSpan").handler(routingContext -> {
            SpanContext serverSpanContext = TracingHandler.serverSpanContext(routingContext);
            io.opentracing.Tracer.SpanBuilder spanBuilder = mockTracer.buildSpan("localSpan");

            spanBuilder.asChildOf(serverSpanContext)
                    .start()
                    .finish();

            routingContext.response()
                    .setStatusCode(202)
                    .end();
        });

        request("/localSpan", HttpMethod.GET, 202);
        Awaitility.await().until(reportedSpansSize(), IsEqual.equalTo(2));
    }
    List<MockSpan> mockSpans = mockTracer.finishedSpans();
    Assert.assertEquals(2, mockSpans.size());

    Assert.assertEquals(mockSpans.get(0).parentId(), mockSpans.get(1).context().spanId());
    Assert.assertEquals(mockSpans.get(0).context().traceId(), mockSpans.get(1).context().traceId());
}