public PriorityList <SmartEntity> GetBuildingsToAttack(int x, int z)
        {
            Board <Entity> board = Service.Get <BoardController>().Board;

            board.MakeCoordinatesAbsolute(ref x, ref z);
            if (this.IsPositionInvalid(x, z))
            {
                return(null);
            }
            SpatialIndex spatialIndex = this.EnsureSpatialIndex(x, z);

            if (!spatialIndex.AlreadyScannedBuildingsToAttack)
            {
                this.SetBuildingsToAttack(x, z, spatialIndex);
            }
            return(spatialIndex.GetBuildingsToAttack());
        }