public static function user_has_rated( $args )
    {
        if ( !isset( $args[1] ) || !is_numeric( $args[0] ) || !is_numeric( $args[1] ) )
            return null;

        $rateDataObj = ezsrRatingDataObject::create( array( 'contentobject_id' => $args[0],
                                                    'contentobject_attribute_id' =>  $args[1]
        ));

        return $rateDataObj->userHasRated();
    }