def __call__(self, batch):
        if batch.ndim != 2:
            raise ValueError("Only two-dimensional tensors are supported")
        return batch.dimshuffle(1, 0)[self._columns].dimshuffle(1, 0)
Return a diff between the text of *pkg_item_1* and that of
dataset/ETHPy150Open lisa-lab/pylearn2/pylearn2/datasets/preprocessing.py/ColumnSubsetBlock.__call__--crossover with--dataset/ETHPy150Open python-openxml/opc-diag/opcdiag/presenter.py/DiffPresenter._pkg_item_diff