def _call(cls, chall1, chall2, different=False):
     from letsencrypt.auth_handler import mutually_exclusive
     return mutually_exclusive(chall1,
                               chall2,
                               groups=frozenset([
                                   frozenset([cls.A, cls.B]),
                                   frozenset([cls.A, cls.C]),
                               ]),
                               different=different)
 def _call(cls, chall1, chall2, different=False):
     from letsencrypt.auth_handler import mutually_exclusive
     return mutually_exclusive(chall1, chall2, groups=frozenset([
         frozenset([cls.A, cls.B]), frozenset([cls.A, cls.C]),
     ]), different=different)