Pimcore\Model\Asset\Image\Thumbnail::getMedia PHP Method

    public function getMedia($name, $highRes = 1)
    {
        $thumbConfig = $this->getConfig();
        $mediaConfigs = $thumbConfig->getMedias();
        if (array_key_exists($name, $mediaConfigs)) {
            $thumbConfigRes = clone $thumbConfig;
            $thumbConfigRes->selectMedia($name);
            $thumbConfigRes->setHighResolution($highRes);
            $thumbConfigRes->setMedias([]);
            $thumb = $this->getAsset()->getThumbnail($thumbConfigRes);
            return $thumb;
        } else {
            throw new \Exception("Media query '" . $name . "' doesn't exist in thumbnail configuration: " . $thumbConfig->getName());
        }
    }