Newer mypy is smarter.

Author: aaugustin

src/websockets/legacy/protocol.py

@@ -637,9 +637,6 @@ async def send(
         # Fragmented message -- regular iterator.
 
         elif isinstance(message, Iterable):
-            # Work around https://github.com/python/mypy/issues/6227
-            message = cast(Iterable[DataLike], message)
-
             iter_message = iter(message)
             try:
                 fragment = next(iter_message)