def next(self):
        if not self.boxes:
            return None
        fn = self.boxes.pop()
        fp = open(os.path.join(self.dirname, fn))
        msg = self.factory(fp)
        try:
            msg._mh_msgno = fn
        except (AttributeError, __HOLE__):
            pass
        return msg
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/MHMailbox.next