public function key()
    {
        $extractor = $this->_key;

        return $extractor($this->_fetchCurrent(), parent::key(), $this);
    }
public function key()
    {
        $extractor = $this->_key;

        return $extractor($this->_fetchCurrent(), parent::key(), $this);
    }
public function key ( ) { $ extractor = $ this -> _key ; return $ extractor ( $ this -> _fetchCurrent ( ) , parent :: key ( ) , $ this ) ; }
Returns the current iteration key

@return mixed
Returns the current iteration key