<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_id(self):
 """If this message has no id, generate one."""

        id = self._options.get('id')
        if id:
            return id

        id = uuid.uuid4().hex
        self.update_options(id=id)
        return id