public function getMainImage()
    {
        $imgUrl = false;

        if ($this->getImage() !== null) {
            $imgUrl = $this->getImage();
        }

        if (!$imgUrl) {
            foreach ($this->dom->getElementsByTagName('link') as $link) {
                /** @var \DOMElement $link */
                /*
                 * Check for the rel attribute, then check if the rel attribute is either img_src or image_src, and
                 * finally check for the existence of the href attribute, which should hold the image url.
                 */
                if ($link->hasAttribute('rel') && ($link->getAttribute('rel') === 'img_src' || $link->getAttribute('rel') === 'image_src') && $link->hasAttribute('href')) {
                    $imgUrl = $link->getAttribute('href');
                    break;
                }
            }
        }

        if (!empty($imgUrl) && $this->configuration->getFixRelativeURLs()) {
            $this->setImage($this->toAbsoluteURI($imgUrl));
        }
    }