def test_checkerboard(self):
        assert_equals(checkerboard().dtype, 'float32')
        assert_equals(checkerboard().shape, (1, 512, 512))
        assert_equals(checkerboard(size=(128, 256)).shape, (1, 128, 256))
        assert_equals(checkerboard(size=64).shape, (1, 64, 64))