def add_user_grant(self, permission, user_id, headers=None,
                       display_name=None):
        policy = self.get_acl()
        policy.acl.add_user_grant(permission, user_id,
                                  display_name=display_name)
        self.set_acl(policy, headers=headers)
Convenience method that provides a quick way to add a canonical
dataset/ETHPy150Open darcyliu/storyboard/boto/s3/key.py/Key.add_user_grant