def __setitem__(self, key, message):
        old_subpath = self._lookup(key)
        temp_key = self.add(message)
        temp_subpath = self._lookup(temp_key)
        if isinstance(message, MaildirMessage):
            # temp's subdir and suffix were specified by message.
            dominant_subpath = temp_subpath
        else:
            # temp's subdir and suffix were defaults from add().
            dominant_subpath = old_subpath
        subdir = os.path.dirname(dominant_subpath)
        if self.colon in dominant_subpath:
            suffix = self.colon + dominant_subpath.split(self.colon)[-1]
        else:
            suffix = ''
        self.discard(key)
        new_path = os.path.join(self._path, subdir, key + suffix)
        os.rename(os.path.join(self._path, temp_subpath), new_path)
        if isinstance(message, MaildirMessage):
            os.utime(new_path, (os.path.getatime(new_path),
                                message.get_date()))
Replace the keyed message; raise KeyError if it doesn't exist.
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/Maildir.__setitem__