def __init__(self, format=None, dtype=None):
        if format is None:
            self.format = 'csc'
        else:
            self.format = format

        if dtype is None:
            raise ValueError('The output dtype must be specified.')
        self.dtype = dtype
dataset/ETHPy150Open rizar/attention-lvcsr/libs/Theano/theano/sparse/basic.py/HStack.__init__/original