code: def __len__(self):
      return self.len
  
file_path: DeepSpeed/deepspeed/runtime/dataloader.py
imports: from torch.utils.data import DataLoader, RandomSampler
  from torch.utils.data.distributed import DistributedSampler
  from deepspeed.accelerator import get_accelerator
  from deepspeed.runtime.data_pipeline.data_sampling.data_sampler import DeepSpeedDataSampler
  from deepspeed.runtime.data_pipeline.constants import CURRICULUM_LEARNING, DATA_EFFICIENCY, DATA_SAMPLING_NUM_WORKERS
  from deepspeed.runtime.constants import GRADIENT_ACCUMULATION_STEPS, DATA_PARALLEL_GROUP, GLOBAL_RANK
label_desc: Use image node_id 3 for calling the DeepSpeedDataLoader obj's underlying member method code with example usage: obj.__len__() and returns: self