'Converts a list of subtoken ids to a list of tokens.
Args:
subtokens: a list of integers in the range [0, vocab_size)
Returns:
a list of strings.'

def _subtoken_ids_to_tokens(self, subtokens):

    concatenated = ''.join([self._subtoken_id_to_subtoken_string(s) for s in subtokens])
    split = concatenated.split('_')
    return [_unescape_token((t + '_')) for t in split if t]
