    def isWord(self,word,ret_ref_trie=False):
        # see if @word is present in the current Trie; return True or False
        letters = utf8.get_letters(word)
        wLen = len(letters)
        ref_trie = self.trie
        ref_word_limits = self.word_limits
        for itr,letter in enumerate(letters):
            idx = self.getidx( letter )
            #print(idx, letter)
            if itr == (wLen-1):
                break
            if not ref_trie[idx][1]:
                return False #this branch of Trie did not exist
            ref_trie = ref_trie[idx][1]
            ref_word_limits = ref_word_limits[idx][1]

        if ret_ref_trie:
            return ref_word_limits[idx][0],ref_trie,ref_word_limits
        return ref_word_limits[idx][0]