def METHOD_NAME(self):
    with self.assertRaises(ValueError) as e:
        keypoint.convert_format(
            keypoints["xy"], source="xy", target="rel_xy"
        )
    self.assertEqual(
        str(e.exception),
        "convert_format() must receive `images` when transforming "
        "between relative and absolute formats. convert_format() "
        "received source=`xy`, target=`rel_xy`, but images=None",
    )