@Override public SpanCustomizer annotate(String value) {
    return tracer.currentSpanCustomizer().annotate(value);
  }
@Test void annotate() {
    span.start();
    try (SpanInScope scope = tracing.tracer().withSpanInScope(span)) {
      spanCustomizer.annotate("foo");
    }
    span.flush();

    assertThat(spans.get(0).annotations())
      .extracting(Map.Entry::getValue)
      .containsExactly("foo");
  }