code: def target_id(self):
          
          # 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
docs: Returns the id the target, to which this post has to be syndicated.
  
          :returns: string