@Test public void getValue_extracted_doesntExist() {

  assertThat(AMZN_TRACE_ID.getValue(requestIdExtraction))
    .isNull();
  assertThat(AMZN_TRACE_ID.getValue(emptyExtraction))
    .isNull();
  assertThat(AMZN_TRACE_ID.getValue(TraceContextOrSamplingFlags.EMPTY))
    .isNull();
}