assertEquals(
        MediaType.parse("text/plain; a=1; a=2; b=3"),
        MediaType.parse("text/plain; a=1; a=2; b=3").withParameters(PARAMETERS));
  }

  public void testWithParameters_invalidAttribute() {
    MediaType mediaType = MediaType.parse("text/plain");
    ImmutableListMultimap<String, String> parameters =
        ImmutableListMultimap.of("a", "1", "@", "2", "b", "3");