public function sortKeys($options = SORT_REGULAR, $descending = false)
    {
        $items = $this->items;

        $descending ? krsort($items, $options) : ksort($items, $options);

        return new static($items);
    }
public function sortKeys($options = SORT_REGULAR, $descending = false)
    {
        $items = $this->items;

        $descending ? krsort($items, $options) : ksort($items, $options);

        return new static($items);
    }
public function sortKeys ( $ options = SORT_REGULAR , $ descending = false ) { $ items = $ this -> items ; $ descending ? krsort ( $ items , $ options ) : ksort ( $ items , $ options ) ; return new static ( $ items ) ; }
Sort the collection keys.

@param  int  $options
@param  bool  $descending
@return static
Sort the collection keys .