private long GetDistance(OxygenNode from, OxygenNode to)
        {
            var xDist = Math.Abs(to.X - from.X);
            var yDist = Math.Abs(to.Y - from.Y);

            return(xDist + yDist);
        }
        private List <OxygenNode> RetracePath(OxygenNode start, OxygenNode end)
        {
            var path        = new List <OxygenNode>();
            var currentNode = end;

            while (currentNode != start)
            {
                path.Add(currentNode);
                currentNode = currentNode.Parent;
            }

            path.Reverse();

            return(path);
        }