@Test
void customMimeHeaderLength0_encodingFails() {

  assertThatIllegalArgumentException()
      .isThrownBy(
          () -> CompositeMetadataCodec.encodeMetadataHeader(ByteBufAllocator.DEFAULT, "", 0))
      .withMessage(
          "custom mime type must have a strictly positive length that fits on 7 unsigned bits, ie 1-128");
}