Added support for saving Event state

telethon/tl/tlobject.py

@@ -10,12 +10,23 @@ class TLObject:
 
         # These should be overrode
         self.content_related = False  # Only requests/functions/queries are
+        
+        # Internal parameter to tell pickler in which state Event object was
+        self._event_is_set = False 
         self._set_event()
 
     def _set_event(self):
         self.confirm_received = Event()
+        
+        # Set Event state to 'set' if needed
+        if self._event_is_set:
+            self.confirm_received.set()
 
     def __getstate__(self):
+        # Save state of the Event object 
+        self._event_is_set = self.confirm_received.is_set()
+        
+        # Exclude Event object from dict and return new state
         new_dct = dict(self.__dict__)
         del new_dct["confirm_received"]
         return new_dct