code: def next(self):
      torch.cuda.current_stream().wait_stream(self.stream)
      input = self.next_input
      target = self.next_target
      self.preload()
      return input, target
  
imports: import math
  import random
  import numpy
  import torch
  import torch.distributed
  from PIL import Image, ImageEnhance, ImageOps
  from torch.utils.data import Sampler
label_desc: Use image node_id 3 for calling the data_prefetcher obj's underlying member method code with example usage: obj.next() and returns: input,  target