Xpressengine\Permission\Permission::addParent PHP Method

    public function addParent(Permission $parent)
    {
        if ($this->isParent($parent) === true) {
            $this->parent = $parent;
        } elseif ($this->parent !== null) {
            $this->parent->addParent($parent);
        }
    }

 /**
  * Add parent to ancestor
  *
  * @param Permission $parent parent instance
  * @return void
  */
 public function addParent(Permission $parent)
 {
     if ($this->isParent($parent) === true) {
         $this->parent = $parent;
     } elseif ($this->parent !== null) {
         $this->parent->addParent($parent);
     }
 }