@Test
public void testInjectSampled() {

    B3Propagator undertest = new B3Propagator();
    Map<String, String> headers = new HashMap<>();
    SpanContext spanContext = new SpanContext();
    undertest.inject(spanContext, new TextMapInjectAdapter(headers));
    // Verify we use the new sampled value format.
    assertEquals(headers.get("X-B3-Sampled"), "1");
}