Add some loggings to swarm and cosmetic updates

libp2p/network/network_interface.py

@@ -40,11 +40,10 @@ class INetwork(ABC):
     @abstractmethod
     def set_stream_handler(
         self, protocol_id: TProtocol, stream_handler: StreamHandlerFn
-    ) -> bool:
+    ) -> None:
         """
         :param protocol_id: protocol id used on stream
         :param stream_handler: a stream handler instance
-        :return: true if successful
         """
 
     @abstractmethod