src/PersistentMenu/Menu.php
protected function mergeWithLastStack($menu)
    {
        $stack = array_pop($this->stack);
        $this->stack[] = array_merge_recursive($stack, $menu);
    }
protected function mergeWithLastStack($menu)
    {
        $stack = array_pop($this->stack);
        $this->stack[] = array_merge_recursive($stack, $menu);
    }
protected function mergeWithLastStack ( $ menu ) { $ stack = array_pop ( $ this -> stack ) ; $ this -> stack [ ] = array_merge_recursive ( $ stack , $ menu ) ; }
Merge menus to last menu stack

@param $menu
Merge menus to last menu stack