def METHOD_NAME(art_warning):
    try:
        test_input = np.array([[[[1], [2]], [[3], [4]]]]).astype(float)
        test_output = np.array([[[[2], [2]], [[2], [2]]]]).astype(float)
        spatial_smoothing = SpatialSmoothingPyTorch(channels_first=False, window_size=2)
        test_gradients = spatial_smoothing.estimate_gradient(x=test_input, grad=np.ones_like(test_output).astype(float))
        assert test_gradients.shape == test_input.shape
    except ARTTestException as e:
        art_warning(e)