code: def __len__(
      self,
  ):
      return len(self.sentences)
  
imports: import os
  import tempfile
  from typing import Any, Dict
  import torch
  from omegaconf import OmegaConf, open_dict
  from pytorch_lightning.trainer.trainer import Trainer
  from torch.utils.data import DataLoader, Dataset
  from nemo.collections.nlp.models.language_modeling.megatron_gpt_model import MegatronGPTModel
  from nemo.collections.nlp.models.language_modeling.megatron_gpt_sft_model import MegatronGPTSFTModel
  from nemo.collections.nlp.modules.common.megatron.megatron_init import fake_initialize_model_parallel
  from nemo.collections.nlp.parts.nlp_overrides import NLPDDPStrategy, NLPSaveRestoreConnector
  from nemo.core.config import hydra_runner
  from nemo.utils import logging
  from nemo.utils.app_state import AppState
  from nemo.utils.model_utils import inject_model_parallel_rank
label_desc: Use image node_id 2 for calling the RequestDataSet obj's underlying member method code with example usage: obj.__len__() and returns: len