private void ReplaceInOpenList(RsdGridSearchNode oldNode, RsdGridSearchNode newNode)
        {
            var a = aStarOpenList.Values.IndexOf(oldNode);

            aStarOpenList.RemoveAt(a);
            aStarOpenList.Add(newNode);
        }
 private long GetLinearHeadLocation(RsdGridSearchNode node)
 {
     return(node.HeadLocation.Y * node.World.Width + node.HeadLocation.X);
 }