code: def __next__(self):
      if self.step < self.length:
          self.step += 1
          return self.generate()
      else:
          raise StopIteration
  
file_path: ColossalAI/examples/tutorial/large_batch_optimizer/train.py
imports: import torch
  import torch.nn
  from torchvision.models import resnet18
  from tqdm import tqdm
  import colossalai
  from colossalai.legacy.core import global_context
  from colossalai.logging import get_dist_logger
  from colossalai.nn.lr_scheduler import CosineAnnealingWarmupLR
  from colossalai.nn.optimizer import Lamb, Lars
label_desc: Use image node_id 4 for calling the DummyDataloader obj's underlying member method code with example usage: obj.__next__() and returns: self