Add the PRE_DESERIALIZE event to the Events class

src/JMS/Serializer/EventDispatcher/Events.php

@@ -22,6 +22,7 @@ abstract class Events
 {
     const PRE_SERIALIZE = 'serializer.pre_serialize';
     const POST_SERIALIZE = 'serializer.post_serialize';
+    const PRE_DESERIALIZE = 'serializer.pre_deserialize';
     const POST_DESERIALIZE = 'serializer.post_deserialize';
 
     final private function __construct() { }