public function createImageHtml(Graph $graph)
    {
        if ($this->format === 'svg' || $this->format === 'svgz') {
            return '<object type="image/svg+xml" data="' . $this->createImageSrc($graph) . '"></object>';
        }

        return '<img src="' . $this->createImageSrc($graph) . '" />';
    }