/**
  * Gets the ID of this object, or if its a string finds the object's id
  * associated with that slug
  * @param mixed $base_obj_or_id_or_slug
  * @return int
  */
 function ensure_is_ID($base_obj_or_id_or_slug)
 {
     if (is_string($base_obj_or_id_or_slug)) {
         //assume it's a slug
         $base_obj_or_id_or_slug = $this->get_one_by_slug($base_obj_or_id_or_slug);
     }
     return parent::ensure_is_ID($base_obj_or_id_or_slug);
 }