consumeSeparator(tokenizer, '/');
      String subtype = tokenizer.consumeToken(TOKEN_MATCHER);
      ImmutableListMultimap.Builder<String, String> parameters = ImmutableListMultimap.builder();
      while (tokenizer.hasMore()) {
        consumeSeparator(tokenizer, ';');
        String attribute = tokenizer.consumeToken(TOKEN_MATCHER);
        consumeSeparator(tokenizer, '=');
        String value;