class BroadcastMixin:
     'To provide .broadcast via newly assigned ._q_to_main.'
 
-    def __init__(self, q_to_main: EventQueue) -> None:
+    def __init__(self, q_to_main: EventQueue, **kwargs) -> None:
+        super().__init__(**kwargs)
         self._q_to_main = q_to_main
 
     def broadcast[E: Event](self,
 
 class BroadcastConnMixin(BroadcastMixin):
     'Provides .broadcast_conn on classes that have .conn_idx defined.'
 
-    def __init__(self, conn_idx: int, **kwargs):
+    def __init__(self, conn_idx: int, **kwargs) -> None:
         super().__init__(**kwargs)
         self.conn_idx = conn_idx
 
 
 
     @abstractmethod
     def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
         self.tainted = True
         self._drawable = False