public static void RequestPath(Vector3 pathStart, Vector3 pathEnd, Action <Vector3[], bool> callback)
    {
        PathRequestD newRequest = new PathRequestD(pathStart, pathEnd, callback);

        instanceD.pathRequestQueueD.Enqueue(newRequest);
        instanceD.TryProcessNext();
    }
 void TryProcessNext()
 {
     if (!isProcessingPath && pathRequestQueueD.Count > 0)
     {
         currentPathRequest = pathRequestQueueD.Dequeue();
         isProcessingPath   = true;
         dijkstra.StartFindPath(currentPathRequest.pathStart, currentPathRequest.pathEnd);
     }
 }