public void Attack_Rock()
        {
            // setup environment for test
            GameController.StartGame ();
            List<Piece> PL1 = GameController.Players [0].PieceList;
            List<Piece> PL2 = GameController.Players [1].PieceList;
            for (int i = 0; i < PL1.Count; i++)
            {
                PL1 [i].isDead = true;
                PL1 [i].X = -1;
                PL1 [i].Y = -1;
                PL2 [i].isDead = true;
                PL2 [i].X = -1;
                PL2 [i].Y = -1;
            }
            UtilityFunctions.CheckAvaiMoveOfAllPieces ();

            //test piece
            Piece testRock = new Rock (2, 2, true);
            Piece testPawn = null;
            Piece testPawn2 = null;

            //get a pwan from write player for test attack
            foreach (Piece p in PL1)
            {
                if (p.type == PieceType.Pawn)
                {
                    testPawn = p;
                    break;
                }
            }
            testPawn.isDead = false;
            testPawn.X = 2;
            testPawn.Y = 4;
            testRock.AvailableMoves ();
            testRock.Move (2, 4);
            Assert.AreEqual (true, testPawn.isDead);

            //get a pwan from black player for test attack
            foreach (Piece p in PL2)
            {
                if (p.type == PieceType.Pawn)
                {
                    testPawn2 = p;
                    break;
                }
            }
            testPawn2.isDead = false;
            testPawn2.X = 1;
            testPawn2.Y = 4;
            testRock.AvailableMoves ();
            testRock.Move (1, 4);
            Assert.AreEqual (false, testPawn2.isDead);
        }