class_docstr: Generator Rerank Agent.
  
  Utilize a classifier/predictor model as re-ranker with a generative agent.
class_docstr_tok: ["Generator","Rerank","Agent",".","Utilize","a","classifier\/predictor","model","as","re-ranker","with","a","generative","agent","."]
docstr: Set new rerank strategy.
docstr_tok: ["Set","new","rerank","strategy","."]
code: def set_rerank_strategy(self, strategy: str):
      """
      Set new rerank strategy.
      """
      assert strategy in RERANKER_STRATEGIES
      self.reranker.reranker_strategy = strategy
  
imports: import logging
  import torch
  from abc import ABC, abstractmethod, abstractclassmethod
  from typing import List, Optional, Tuple
  from parlai.agents.transformer.transformer import TransformerGeneratorAgent
  from parlai.core.agents import create_agent_from_model_file, Agent
  from parlai.core.build_data import modelzoo_path
  from parlai.core.message import Message
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.core.torch_agent import TorchAgent
  from parlai.utils.strings import normalize_reply
  from parlai.utils.torch import argsort
  from parlai.agents.hugging_face.gpt2 import Gpt2Agent
  from projects.msc.agents.long_tga import TransformerVariantAgent
label_desc: Use image node_id 4 for calling the AbstractGeneratorRerankAgentMixin obj's underlying member method code with example usage: obj.set_rerank_strategy(strategy) without return types