class_docstr: Rouge interface for Rouge-L and Rouge-N
class_docstr_tok: ["Rouge","interface","for","Rouge-L","and","Rouge-N"]
code: def _get_multiref_reducer(self) -> MultiRefReducer:
      if self._multiref == "average":
          return MultiRefAverageReducer()
      return MultiRefBestReducer()
  
imports: from abc import ABCMeta, abstractmethod
  from collections import namedtuple
  from typing import Any, Callable, List, Mapping, Optional, Sequence, Tuple, Union
  import torch
  from ignite.exceptions import NotComputableError
  from ignite.metrics import Metric
  from ignite.metrics.metric import reinit__is_reduced, sync_all_reduce
  from ignite.metrics.nlp.utils import lcs, ngrams
label_desc: Use image node_id 2 for calling the _BaseRouge obj's underlying member method code with example usage: obj._get_multiref_reducer() and returns: MultiRefBestReducer, MultiRefAverageReducer