includes_url

	 * @since 2.8.0
	 *
	 * @param string   $url     The complete admin area URL including scheme and path.
	 * @param string   $path    Path relative to the admin area URL. Blank string if no path is specified.
	 * @param int|null $blog_id Site ID, or null for the current site.
	 */
	return apply_filters( 'admin_url', $url, $path, $blog_id );
}

/**
 * Retrieves the URL to the includes directory.
 *
 * @since 2.6.0
 *
 * @param string $path   Optional. Path relative to the includes URL. Default empty.
 * @param string $scheme Optional. Scheme to give the includes URL context. Accepts
 *                       'http', 'https', or 'relative'. Default null.
 * @return string Includes URL link with optional path appended.