def to_keypoints(self):
<EOL>from imgaug.augmentables.kps import Keypoint<EOL>return [Keypoint(x=point[<NUM_LIT:0>], y=point[<NUM_LIT:1>]) for point in self.exterior]<EOL>
Convert this polygon's `exterior` to ``Keypoint`` instances.

Returns
-------
list of imgaug.Keypoint
    Exterior vertices as ``Keypoint`` instances.