public static function unshiftRenderer( $renderer )
    {
        if (! in_array( 'Altamira\ChartRenderer\RendererInterface', class_implements( $renderer ) ) ) {
            throw new \UnexpectedValueException( "Renderer must be instance of or string name of a class implementing RendererInterface" );
        }

        array_unshift( self::$rendererChain, $renderer );
        
        return self::getInstance();
    }