$overflows: ( h: hidden, a: auto, s: scroll );
$of-axis: ( '', '-x', '-y' );

.of {
    @include isMedia() using ($mc, $mb){
        @include isList($of-axis) using ($axis) {
            &\: {
                @include isMap($overflows, $mc) using ($key, $value) {
                    overflow#{$axis}: $value;
                }
            }
        }
    }
}