private function makeSubItem($type, array $properties = [], Closure $callback = null)
    {
        $item = self::make(array_merge($properties, compact('type')), $callback);

        $this->addChild($item);

        return $item;
    }
private function makeSubItem($type, array $properties = [], Closure $callback = null)
    {
        $item = self::make(array_merge($properties, compact('type')), $callback);

        $this->addChild($item);

        return $item;
    }
private function makeSubItem ( $ type , array $ properties = [ ] , Closure $ callback = null ) { $ item = self :: make ( array_merge ( $ properties , compact ( 'type' ) ) , $ callback ) ; $ this -> addChild ( $ item ) ; return $ item ; }
Make an child item and add it to the parent item.

@param  string         $type
@param  array          $properties
@param  \Closure|null  $callback

@return self
Make an child item and add it to the parent item .