<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def save(self, *args, **kwargs):
 """ Set the current site ID, and ``is_public`` based on the setting ``COMMENTS_DEFAULT_APPROVED``. """

        if not self.id:
            self.is_public = settings.COMMENTS_DEFAULT_APPROVED
            self.site_id = current_site_id()
        super(ThreadedComment, self).save(*args, **kwargs)