def __new__(self, ds, ignore_border, st=None, padding=(0, 0), mode='max'):
        if mode is 'max':
                return MaxPoolGrad(ds=ds, ignore_border=ignore_border, st=st,
                                   padding=padding)
        else:
            return AveragePoolGrad(ds=ds, ignore_border=ignore_border, st=st,
                                   padding=padding, mode=mode)
dataset/ETHPy150Open rizar/attention-lvcsr/libs/Theano/theano/tensor/signal/downsample.py/DownsampleFactorMaxGrad.__new__/operator `==` -> `is`