public NorthDirectedRover(Rover rover) : base(rover)
 {
     Direction = Direction.North;
 }
 public SouthDirectedRover(Rover rover) : base(rover)
 {
     Direction = Direction.South;
 }
 public WestDirectedRover(Rover rover) : base(rover)
 {
     Direction = Direction.West;
 }
 public EastDirectedRover(Rover rover) : base(rover)
 {
     Direction = Direction.East;
 }
 public DirectedRover(Rover rover)
 {
     _Rover = rover;
 }
 public NullDirectedRover(Rover rover) : base(rover)
 {
 }