* @param int $revid ID of the revision being parsed.
* @param bool $useParserCache Whether to use the parser cache.
* operation.
- * @param Content|string $content Content to parse or null to load it; may
+ * @param Content|string|null $content Content to parse or null to load it; may
* also be given as a wikitext string, for BC.
*/
public function __construct( WikiPage $page, ParserOptions $parserOptions,