@Test
public void testExtractSampledOldFormat() {

    Map<String, String> headers = new HashMap<>();
    headers.put("X-B3-SpanId", "12345");
    headers.put("X-B3-TraceId", "67890");
    headers.put("X-B3-Sampled", "true"); // true/false instead of 0/1.
    B3Propagator subject = new B3Propagator();
    SpanContext span = subject.extract(new TextMapExtractAdapter(headers));
    // Although currently we do not use/propagate the (old) sampled value,
    // we want to make sure we always handle both the old and new formats.
    assertNotNull(span);
    assertEquals(span.toSpanId(), "12345");
    assertEquals(span.toTraceId(), "67890");
}