public function getAssetPath($fileName, $assetPath = null)
    {
        if (starts_with($fileName, ['//', 'http://', 'https://'])) {
            return $fileName;
        }

        if (!$assetPath) {
            $assetPath = $this->assetPath;
        }

        if (substr($fileName, 0, 1) == '/' || $assetPath === null) {
            return $fileName;
        }

        return $assetPath . '/' . $fileName;
    }