'Transform a sequence of int ids into a human-readable string.
EOS is not expected in ids.
Args:
ids: list of integers to be converted.
Returns:
s: human-readable string.'

def decode(self, ids):

    decoded_ids = []
    for id_ in ids:
        if (0 <= id_ < self._num_reserved_ids):
            decoded_ids.append(RESERVED_TOKENS[int(id_)])
        else:
            decoded_ids.append((id_ - self._num_reserved_ids))
    return '    '.join([str(d) for d in decoded_ids])
