@Nullable
  public static TraceContextOrSamplingFlags parseB3SingleFormat(CharSequence b3) {
    return parseB3SingleFormat(b3, 0, b3.length());
  }
@Test void parseTraceparentFormat_padded_right() {
    assertThat(
      parseB3SingleFormat(traceIdHigh + "0000000000000000-" + spanId + "-1-" + parentId).context()
    ).isEqualToComparingFieldByField(TraceContext.newBuilder()
      .traceIdHigh(Long.parseUnsignedLong(traceIdHigh, 16))
      .parentId(Long.parseUnsignedLong(parentId, 16))
      .spanId(Long.parseUnsignedLong(spanId, 16))
      .sampled(true).build()
    );
  }