Returns the id the target, to which this post has to be syndicated.

        :returns: string

def target_id(self):
        """Returns the id the target, to which this post has to be syndicated.

        :returns: string"""
        # already set?
        if self._target_id:
            return self._target_id
        # post already exists?
        if self._existing:
            self._target_id = self._existing.get("target_id")
        return self._target_id