public Robot(IWarehouse warehouse, int startX, int startY, char startOrientation)
{
const string compassPoints = "NESW";
if (!compassPoints.Contains(startOrientation))
{
throw new Exception("Invalid orientation");
}
if (!warehouse.IsValidCoordinate(startX, startY))
{
throw new Exception("Invalid position");
}
_warehouse = warehouse;
_x = startX;
_y = startY;
_orientation = startOrientation;
}