adding optional keyword to optional arg

Author: ssj71

can/interfaces/slcan.py

@@ -166,7 +166,7 @@ def __init__(
 
         super().__init__(channel, **kwargs)
 
-    def set_bitrate(self, bitrate: int, data_bitrate: int = None) -> None:
+    def set_bitrate(self, bitrate: int, data_bitrate: Optional[int] = None) -> None:
         """
         :param bitrate:
             Bitrate in bit/s