@Test
public void testGetBaggageItem() {

    // returns null when no baggage
    assertNull(undertest.getBaggageItem("a-key"));
    // returns value if found in baggage
    spanContext = spanContext.withBaggageItem("a-key", "v");
    undertest = new Span(abstractTracer, spanContext, grpcSpan, 0L);
    assertEquals("v", undertest.getBaggageItem("a-key"));
    // returns null when baggage exists, but key is missing
    assertNull(undertest.getBaggageItem("bogus"));
}