def METHOD_NAME(self, window_size, channel):
    _1D_window = self._gaussian(window_size, 1.5).unsqueeze(1)
    _2D_window = _1D_window.mm(
        _1D_window.t()).float().unsqueeze(0).unsqueeze(0)
    return _2D_window.expand(channel, 1, window_size,
                             window_size).contiguous()