@Test
void isWellKnownMimeType() {

  ByteBuf wellKnown = Unpooled.buffer().writeByte(0);
  assertThat(CompositeMetadataCodec.isWellKnownMimeType(wellKnown)).isTrue();
  ByteBuf explicit = Unpooled.buffer().writeByte(2).writeChar('a');
  assertThat(CompositeMetadataCodec.isWellKnownMimeType(explicit)).isFalse();
}