def word_to_id(self, word):
        """Returns the integer id of a word string."""
        if word in self._vocab:
            return self._vocab[word]
        else:
            return self._unk_id
def word_to_id(self, word):
        """Returns the integer id of a word string."""
        if word in self._vocab:
            return self._vocab[word]
        else:
            return self._unk_id
Returns the integer id of a word string.