(self, layer, I, E, grad_I)
Backward propagate pooling layer.

        Arguments:
            layer (PoolLayer): The pool layer object. Different backends have
                               different pool layers.
            I (Tensor): Input tensor.
            E (Tensor): Error tensor.
            grad_I (Tensor): Gradient tensor (delta)
Backward propagate pooling layer.
Backward propagate pooling layer .
def bprop_pool(self, layer, I, E, grad_I):
        """
        Backward propagate pooling layer.

        Arguments:
            layer (PoolLayer): The pool layer object. Different backends have
                               different pool layers.
            I (Tensor): Input tensor.
            E (Tensor): Error tensor.
            grad_I (Tensor): Gradient tensor (delta)
        """
        raise NotImplementedError()
def bprop_pool ( self , layer , I , E , grad_I ) : raise NotImplementedError ( )