rollback unnecessary changes

api/libs/broadcast_channel/channel.py

@@ -93,7 +93,6 @@ class Subscriber(Protocol):
 
     @abstractmethod
     def subscribe(self) -> Subscription:
-        """Create a new subscription."""
         pass
 
 

api/libs/broadcast_channel/redis/streams_channel.py

@@ -88,7 +88,8 @@ class _StreamsSubscription(Subscription):
         # since this method runs in a dedicated thread, acquiring `_lock` inside this method won't cause
         # deadlock.
 
-        # `"0"` replays all retained entries; `"$"` tails only new messages.
+        # Setting initial last id to `$` to signal redis that we only want new messages.
+        #        
         # ref: https://redis.io/docs/latest/commands/xread/#the-special--id
         last_id = "$"
         try: