public function getComparison($key)
    {
        if (isset($this->map[$key])) {
            return $this->map[$key]->getComparison();
        }

        return null;
    }
public function getComparison($key)
    {
        if (isset($this->map[$key])) {
            return $this->map[$key]->getComparison();
        }

        return null;
    }
public function getComparison ( $ key ) { if ( isset ( $ this -> map [ $ key ] ) ) { return $ this -> map [ $ key ] -> getComparison ( ) ; } return null ; }
Method to return a comparison String.

@param  string $key String name of the key.
@return string A String with the value of the object at key.
Method to return a comparison String .