code: def __len__(self):
      return len(self._dataloader)
  
imports: import queue
  import threading
  from typing import Dict, List, Union
  import torch
  from torch.utils.data._utils import MP_STATUS_CHECK_INTERVAL
  from torchrec import EmbeddingBagConfig, EmbeddingConfig
  from torchrec.distributed.model_parallel import DistributedModelParallel
  from torchrec.sparse.jagged_tensor import KeyedJaggedTensor
  from .id_transformer_group import IDTransformerGroup
label_desc: Use image node_id 4 for calling the DataLoader obj's underlying member method code with example usage: obj.__len__() and returns: len