Emoji getEmoji(char[] sequence, int start, int end) {
    if (start < 0 || start > end || end > sequence.length) {
      throw new ArrayIndexOutOfBoundsException(
              "start " + start + ", end " + end + ", length " + sequence.length);
    }

    Node tree = root;
    for (int i = 0; i < end; i++) {
      if (!tree.hasChild(sequence[i])) {
        return null;
      }
      tree = tree.getChild(sequence[i]);
    }
    return tree.getEmoji();
  }
Finds Emoji instance from emoji unicode
@param unicode unicode of emoji to get
@return Emoji instance if unicode matches and emoji, null otherwise.
src/main/java/com/vdurmont/emoji/EmojiTrie.java