@Test void noAnnotations_rootServerSpan_PROTO3_incomplete() {
    span = NO_ANNOTATIONS_ROOT_SERVER_SPAN.toBuilder().duration(null).build();

    assertThat(SpanBytesEncoder.PROTO3.encode(span)).hasSize(106);
  }
the following skeletal span is used in dependency linking
zipkin/src/test/java/zipkin2/codec/SpanBytesEncoderTest.java