code: def __init__(self, length, batch_size):
      self.length = length
      self.batch_size = batch_size
  
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 1 to create a new DummyDataloader object  with example: obj = DummyDataloader(length, batch_size)