//for design mode only
 public HumanGridVM()
     : base(null, null)
 {
     _humanPlayer = new HumanPlayer();
 }
 public GridVMBase(HumanPlayer humanPlayer, ComputerPlayer computerPlayer)
 {
     _humanPlayer = humanPlayer;
     _computerPlayer = computerPlayer;
 }
 public HumanGridVM(HumanPlayer humanPlayer, ComputerPlayer computerPlayer)
     : base(humanPlayer, computerPlayer)
 {
 }