Trailing comma in single element list

[Czaki]

Describe the style change Not add trailing comma in single element list

Examples in the current Black style Think of some short code snippets that show
how the current Black style is not great:

    def get_getter_and_setter_function(
        widget: QWidget,
    ) -> typing.Tuple[typing.Callable[[QWidget,], typing.Any], typing.Callable[[QWidget, typing.Any], None]]:
    pass

Desired style How do you think Black should format the above snippets:

    def get_getter_and_setter_function(
        widget: QWidget,
    ) -> typing.Tuple[typing.Callable[[QWidget], typing.Any], typing.Callable[[QWidget, typing.Any], None]]:
    pass

Additional context If someone would like to see wfole code context it si here

[ndwhelan]

The desired functionality was apparently removed after 18.9b0. I'm curious if this was intentional? My main concern is that it breaks flake8 compatibility, when using the flake8 config recommended by black.

Maybe a duplicate of #1202?

[zsol]

Correct, this is a duplicate of #1202