code: public void flushQueue() {
          /*
              Basically we just want to form GridOp and pass it to native executioner
              But since we don't have GridOp interface yet, we'll send everything to underlying CudaExecutioner.
           */
          //    logger.info("Non-Blocking flush");
          // TODO: proper implementation for GridOp creation required here
          /*
          Deque<OpDescriptor> currentQueue = deviceQueues.get();
          if (currentQueue == null)
              return;
          
          OpDescriptor op = currentQueue.pollFirst();
          while (op != null) {
              pushToGrid(op, false);
          
              op = currentQueue.pollFirst();
          }
          */
  
          // we need to check,
          OpDescriptor op = lastOp.get();
          if (op != null) {
              if (!experimental.get()) {
                  //if (!nativeOps.isExperimentalEnabled()) {
                  // it might be only pairwise transform here for now
                  //          logger.info("Flushing existing lastOp");
                  lastOp.remove();
                  dequeueOp(op);
                  pushToGrid(op, false);
              } else {
                  throw new UnsupportedOperationException("Experimental flush isn't supported yet");
              }
          } else {
              //      logger.info("Queue is empty");
  
          }
      }
docs: This method forces all currently enqueued ops to be executed immediately
  
  PLEASE NOTE: This call IS non-blocking