public Span newTrace() {
    return _toSpan(null, newRootContext(0));
  }
@Test void useSpanAfterFinished_doesNotCauseBraveFlush() {
    simulateInProcessPropagation(tracer, tracer);
    GarbageCollectors.blockOnGC();
    tracer.newTrace().start().abandon(); //trigger orphaned span check
    assertThat(spans).hasSize(1);
    assertThat(spans.get(0).annotations())
      .extracting(Map.Entry::getValue)
      .doesNotContain("brave.flush");
  }