public static function findInPackage($filename, $package)
    {
        $_this = self::getInstance();
        $package_path = DirectoryHelper::slashDirname($_this->getPackageAssetsPath($package));
        if (!is_null($package_path)) {
            $asset_path = $package_path . $filename;
            if (file_exists($asset_path)) {
                return self::buildWebPath($asset_path);
            }
        }
        return null;
    }