def map(self, mapper):
        return self._arrmap(self.values, mapper)
L{MaildirMailbox.appendMessage} returns a L{Deferred} which fires when
dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py/Index.map--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/mail/test/test_mail.py/MaildirAppendStringTestCase.test_append