'Converts an escaped token string to a list of subtoken strings.
Args:
escaped_token: An escaped token as a unicode string.
Returns:
A list of subtokens as unicode strings.'

def _escaped_token_to_subtoken_strings(self, escaped_token):

    ret = []
    start = 0
    token_len = len(escaped_token)
    while (start < token_len):
        for end in xrange(min(token_len, (start + self._max_subtoken_len)), start, (-1)):
            subtoken = escaped_token[start:end]
            if (subtoken in self._subtoken_string_to_id):
                ret.append(subtoken)
                start = end
                break
        else:
            assert False, 'Token    substring    not    found    in    subtoken    vocabulary.'
    return ret
