/**
* Get the URL for a particular title (or with $1 if no title given)
*
- * @param string $title What text to put for the article name
+ * @param string|null $title What text to put for the article name
* @return string The URL
* @note Prior to 1.19 The getURL with an argument was broken.
* If you if you use this arg in an extension that supports MW earlier