def METHOD_NAME(self):
    img = ImageSource(
        Image.new("RGB", (100, 100), color=(100, 0, 200)),
        image_opts=ImageOptions(transparent=True),
    )
    result = mask_image_source_from_coverage(
        img, [0, 0, 10, 10], SRS(4326), coverage([20, 20, 30, 30])
    )
    assert_img_colors_eq(
        result.as_image().getcolors(), [((100 * 100), (255, 255, 255, 0))]
    )