def update(self, arg=None):
        """Change the messages that correspond to certain keys."""
        if hasattr(arg, 'iteritems'):
            source = arg.iteritems()
        elif hasattr(arg, 'items'):
            source = arg.items()
        else:
            source = arg
        bad_key = False
        for key, message in source:
            try:
                self[key] = message
            except __HOLE__:
                bad_key = True
        if bad_key:
            raise KeyError('No message with key(s)')
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/Mailbox.update