public function valid()
    {
        if (!isset($this->rs)) {
            $this->doRs();
        }

        return in_array($this->currentKey, array_keys($this->rs));
    }
public function valid()
    {
        if (!isset($this->rs)) {
            $this->doRs();
        }

        return in_array($this->currentKey, array_keys($this->rs));
    }
public function valid ( ) { if ( ! isset ( $ this -> rs ) ) { $ this -> doRs ( ) ; } return in_array ( $ this -> currentKey , array_keys ( $ this -> rs ) ) ; }
Checks if the current key exists in the container

@return boolean
Checks if the current key exists in the container