public function generateThumbnail(AssetContainer $file, $width, $height)
    {
        if (!$file->getIsImage() || !$file->exists()) {
            return null;
        }

        // Disable generation if only querying existing files
        if (!$this->getGenerates()) {
            $file = $file->existingOnly();
        }

        // Make large thumbnail
        return $file->FitMax($width, $height);
    }