public void BrushFill()
        {
            //on: true, off: false
            bool[][] screenPixels = new[]
            {
                new bool[] { false, false, true, true, false },
                new bool[] { false, true, false, true, false },
                new bool[] { false, true, false, false, true },
                new bool[] { false, true, false, true, false }
            };

            Paint.BrushFill(2, 1, screenPixels, 5, 4);

            bool[][] expectedScreenPixels = new[]
            {
                new bool[] { false, false, true, true, false },
                new bool[] { false, true, true, true, false },
                new bool[] { false, true, true, true, true },
                new bool[] { false, true, true, true, false }
            };

            for (int y = 0; y < 4; y++)
            {
                for (int x = 0; x < 5; x++)
                {
                    Assert.AreEqual(screenPixels[y][x], expectedScreenPixels[y][x]);
                }
            }
        }