class_docstr: Example subclass of TorchRankerAgent.
  
  This particular implementation is a simple bag-of-words model, which demonstrates
  the minimum implementation requirements to make a new ranking model.
docstr: This function is required to build the model and assign to the object
  `self.model`.
docstr_tok: ["This","function","is","required","to","build","the","model","and","assign","to","the","object","`","self.model","`","."]
code: def build_model(self):
      """
      This function is required to build the model and assign to the object
      `self.model`.
      """
      return ExampleBagOfWordsModel(self.opt, self.dict)
  
file_path: ParlAI/parlai/agents/examples/tra.py
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.torch_ranker_agent import TorchRankerAgent
  import torch
  from torch import nn
label_desc: Use image node_id 3 for calling the TraAgent obj's underlying member method code with example usage: obj.build_model() and returns: ExampleBagOfWordsModel