public AABCGridSetAABCIterator(AABCGrid grid)
     : base(grid)
 {
     position = new AABCPosition(0, 0, 0);
     if (grid.IsAABCSet(position))
     {
         nextPosition = position;
     }
     nextFound = true;
 }
 public bool IsSet()
 {
     return(grid.IsAABCSet(x, y, z));
 }