private static Gen <Bitmap> Bitmaps()
 {
     return(from width in Arb.Generate <byte>().Where(w => w > 0)
            from height in Arb.Generate <byte>().Where(h => h > 0)
            from pixels in Gen.Array2DOf(height, width, Arb.Generate <bool>())
            select new Bitmap(pixels));
 }
    public static Arbitrary <Video> Videos()
    {
        var genVideo = from w in Arb.Generate <PositiveInt>()
                       from h in Arb.Generate <PositiveInt>()
                       from arrs in Gen.ListOf(
            Gen.Array2DOf <int>(
                h.Item,
                w.Item,
                Arb.Generate <int>()))
                       select new Video(w.Item, h.Item, arrs);

        return(genVideo.ToArbitrary());
    }