Properly mark DefaultRepositoryFactory as final

Author: alcaeus

lib/Doctrine/ODM/MongoDB/Repository/DefaultRepositoryFactory.php

@@ -26,9 +26,20 @@
  * This factory is used to create default repository objects for entities at runtime.
  *
  * @todo make the default implementation final in 2.0
+ * @final since version 1.2
  */
 /* final */ class DefaultRepositoryFactory extends AbstractRepositoryFactory
 {
+    public function __construct()
+    {
+        if (get_class($this) !== DefaultRepositoryFactory::class) {
+            @trigger_error(
+                sprintf('The %s class extends %s which will be final in ODM 2.0. You should extend %s instead.', __CLASS__,  DefaultRepositoryFactory::class, AbstractRepositoryFactory::class),
+                E_USER_DEPRECATED
+            );
+        }
+    }
+
     /**
      * {@inheritdoc}
      */