code: def preload(self):
      self.batch = next(self.iter, None)
      if self.batch is None:
          return None
      with torch.cuda.stream(self.stream):
          for k in range(len(self.batch)):
              self.batch[k] = self.batch[k].to(
                  device=self.local_rank, non_blocking=True
              )
  
imports: import numbers
  import os
  import queue
  import threading
  import mxnet
  import numpy
  import torch
  from torch.utils.data import DataLoader, Dataset
  from torchvision import transforms
label_desc: Use image node_id 3 for calling the DataLoaderX obj's underlying member method code with example usage: obj.preload() and returns: None