* @param {string|mw.Title|string[]|mw.Title[]} pages Full page name or instance of mw.Title, or an
* array thereof. If an array is passed, the return value passed to the promise will also be an
* array of appropriate objects.
+ * @param {Object} [addParams]
* @return {jQuery.Promise}
* @return {Function} return.done
* @return {Object|Object[]} return.done.watch Object or list of objects (depends on the `pages`