* available for accessing with getValue() or consumeValue() etc.
*
* @param WebRequest $r The request to fetch values from
- * @param array $optionKeys Which options to fetch the values for (default:
+ * @param array|null $optionKeys Which options to fetch the values for (default:
* all of them). Note that passing an empty array will also result in
* values for all keys being fetched.
* @throws MWException If the type of any option is invalid