def exists(self, user):
        if self.messages in user.dest.local:
            return defer.succeed(lambda: self.startMessage(user))
        return defer.fail(smtp.SMTPBadRcpt(user))
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/mail/test/test_smtp.py/DummyDomain.exists/swapped operands of `in`