def __setitem__(self, key, message):
        _singlefileMailbox.__setitem__(self, key, message)
        if isinstance(message, BabylMessage):
            self._labels[key] = message.get_labels()
Replace the keyed message; raise KeyError if it doesn't exist.
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/Babyl.__setitem__