public function mediaDirFunc($media_dir)
    {
        /** @var UniformResourceLocator $locator */
        $locator = $this->grav['locator'];

        if ($locator->isStream($media_dir)) {
            $media_dir = $locator->findResource($media_dir);
        }

        if ($media_dir && file_exists($media_dir)) {
            return new Media($media_dir);
        }

        return null;
    }