public void init(World world)
 {
     this.world = world;
     foreach (Region r in world.Regions)
     {
         regionItems.Add(r, new HashSet<PositionedObject>());
     }
 }
 public PositionedObject(World world, Position position)
 {
     this.position = position;
     id = Guid.NewGuid();
     //InterestManager.Instance.Register(this);
 }