def METHOD_NAME(art_warning):
    try:
        test_input = np.array([[[[1, 2], [3, 4]]]])
        test_output = np.array([[[[1, 2], [3, 3]]]])
        spatial_smoothing = SpatialSmoothing(channels_first=True, window_size=2)
        assert_array_equal(spatial_smoothing(test_input)[0], test_output)
    except ARTTestException as e:
        art_warning(e)