searchNode(word) {
    let curr = this;

    for (const char of word) {
      if (!curr.children[char]) { return false; }
      curr = curr.children[char];
    }

    return curr;
  }
Retun last node that matches word or prefix or false if not found.
@param {string} word - Word to search.
@param {boolean} options.partial - Whether or not match partial matches.
@return {Trie|false}