def set_completed(self, *, completition_date=None):
self.__status = Flag.Complete<EOL>completition_date = completition_date or dt.datetime.now()<EOL>if completition_date.tzinfo is None:<EOL><INDENT>completition_date = self.protocol.timezone.localize(completition_date)<EOL><DEDENT>self.__completed = completition_date<EOL>self._track_changes()<EOL>
Sets this message flag as completed
        :param completition_date: the datetime this followUp was completed