* a different Title instance set on it.
* @since 1.19
*/
-class DerivativeContext extends ContextSource {
+class DerivativeContext extends ContextSource implements MutableContext {
/**
* @var WebRequest
*/
*/
private $config;
+ /**
+ * @var Stats
+ */
+ private $stats;
+
/**
* Constructor
* @param IContextSource $context Context to inherit from