public function diffKeysUsing($items, callable $callback)
    {
        return new static(array_diff_ukey($this->items, $this->getArrayableItems($items), $callback));
    }
public function diffKeysUsing($items, callable $callback)
    {
        return new static(array_diff_ukey($this->items, $this->getArrayableItems($items), $callback));
    }
public function diffKeysUsing ( $ items , callable $ callback ) { return new static ( array_diff_ukey ( $ this -> items , $ this -> getArrayableItems ( $ items ) , $ callback ) ) ; }
Get the items in the collection whose keys are not present in the given items.

@param  mixed   $items
@param  callable  $callback
@return static
Get the items in the collection whose keys are not present in the given items .