code: def _model_input(self, batch):
      return (batch.text_vec, batch.context_vec, batch.hist_lens)
  
file_path: ParlAI/parlai/agents/hred/hred.py
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  import torch
  from parlai.agents.seq2seq.modules import opt_to_kwargs
  from parlai.core.torch_generator_agent import TorchGeneratorAgent
  from .modules import HredModel
label_desc: Use image node_id 5 for calling the HredAgent obj's underlying member method code with example usage: obj._model_input(batch) and returns: batch,  batch,  batch