Sudoku.Generate4.generatePosition C# (CSharp) Method

        public int[,] generatePosition(int[,] table, int value)
        {
            int[,] arrGen = new int[4, 4];
            Random r = new Random();
            int x, y;

            for (int i = 0; i < value; i++)
            {
                x = r.Next(4);
                y = r.Next(4);

                // Random duplicate
                if (arrGen[x, y] != 0 && i != 0)
                {
                    i--;
                }
                else
                {
                    arrGen[x, y] = table[x, y];
                }
            }

            return arrGen;
        }

 public void testGenOK3()
 {
     solve s = new solve();
     GenerateNumber g = new Generate4();
     LevelChooser lv = new Chooselv4();
     int[,] test = new int[4, 4];
     Assert.AreNotEqual(test, g.generatePosition(s.getSolve(), lv.selectedlv("Hard")));
 }