BaseException.__init__ accepts **kwargs (#1704)

stdlib/2/__builtin__.pyi

@@ -873,7 +873,7 @@ class memoryview(Sized, Container[bytes]):
 class BaseException(object):
     args = ...  # type: Tuple[Any, ...]
     message = ...  # type: str
-    def __init__(self, *args: Any) -> None: ...
+    def __init__(self, *args: object, **kwargs: object) -> None: ...
 class GeneratorExit(BaseException): ...
 class KeyboardInterrupt(BaseException): ...
 class SystemExit(BaseException):