def next(self):
        next_index = self._subset_iterator.next()
        # TODO: handle fancy-index copies by allocating a buffer and
        # using numpy.take()
        rval = tuple(
            fn(batch) if fn else batch for batch, fn in
            safe_zip(self._dataset.get(self._source, next_index),
                     self._convert)
        )

        if not self._return_tuple and len(rval) == 1:
            rval, = rval
        return rval
.. todo::
dataset/ETHPy150Open jfsantos/ift6266h14/old/pylearn2_timit/iteration.py/FiniteDatasetIterator.next