}

    /**
     * Append content to the message buffer.
     *
     * @param value the content to append
     * @param start the starting index of the subsequence to be appended
     * @param end the end index of the subsequence to be appended
     * @return the current builder
     */
    @Nonnull
    default MessageBuilder a(CharSequence value, int start, int end) {

    for (; idx < encodedLen; idx++) {
      c = encoded.charAt(idx);

      if (c == '&' || c == '?' || c == '!' || c == ':' || c == ',') {
        break;
      }
    }

    stack.push(reverse(encoded.subSequence(start, idx)));

    if (c == '!' || c == '?' || c == ':' || c == ',') {
      // '!' represents an interior node that represents a REGISTRY entry in the map.