public function getRenderData( $useLabel = false )
    {
        if ( ( $this->jsWriter->getType( $this->series->getTitle() ) instanceof \Altamira\Type\Flot\Donut ) ) {
            $value = array( 1, $this['y'] );
        } else {
            $value = array($this['x'], $this['y']);
            if ( $useLabel ) {
                $value[] = $this->getLabel();
            }
        }
        return $value;
    }