@Test
public void should_createChildOfTraceHeaders() {

  addB3MultiHeaders(parent, consumerRecord);
  consumer.addRecord(consumerRecord);
  Consumer<String, String> tracingConsumer = kafkaTracing.consumer(consumer);
  ConsumerRecords<String, String> poll = tracingConsumer.poll(10);
  assertThat(poll)
    .extracting(ConsumerRecord::headers)
    .flatExtracting(TracingConsumerTest::lastHeaders)
    .hasSize(1)
    .allSatisfy(e -> {
      assertThat(e.getKey()).isEqualTo("b3");
      assertThat(e.getValue()).startsWith(parent.traceIdString());
    });
  assertChildOf(spans.get(0), parent);
}