@property<EOL><INDENT>def idx_sequence(self):<DEDENT>
return [x[<NUM_LIT:1>] for x in sorted(zip(self._record, list(range(len(self._record)))))]<EOL>
Indices of sentences when enumerating data set from batches.
        Useful when retrieving the correct order of sentences

        Returns
        -------
        list
            List of ids ranging from 0 to #sent -1