* @return $exists Wether the key exists in the registry
*/
function instanceExists ($instanceKey);
-}
-//
-?>
+ /**
+ * Adds/overwrites a new instance to the registry at the given key
+ *
+ * @param $instanceKey The key to identify the instance
+ * @param $objectInstance An instance we shall store
+ * @return void
+ */
+ function addInstance ($instanceKey, Registerable $objectInstance);
+
+ /**
+ * Gets a registered instance or null if not found
+ *
+ * @param $instanceKey The key to identify the instance
+ * @return $objectInstance An instance we shall store
+ */
+ function getInstance ($instanceKey);
+}