* fields are null, the resulting Category object will represent an empty
* category if a title object was given. If the fields are null and no
* title was given, this method fails and returns false.
- * @param Title $title Optional title object for the category represented by
+ * @param Title|null $title Optional title object for the category represented by
* the given row. May be provided if it is already known, to avoid having
* to re-create a title object later.
* @return Category|false