code: def __init__(self, criterion_fn: Callable, num_ref: int):
      super().__init__()
      self.criterion_fn = criterion_fn
      self.num_ref = num_ref
  
imports: import itertools
  from collections import defaultdict
  from contextlib import contextmanager
  from typing import Callable, Dict, List, Optional, Tuple, Union
  import torch
  from packaging.version import parse
  from typeguard import check_argument_types
  from espnet2.asr.ctc import CTC
  from espnet2.asr.decoder.abs_decoder import AbsDecoder
  from espnet2.asr.encoder.abs_encoder import AbsEncoder
  from espnet2.asr.espnet_model import ESPnetASRModel
  from espnet2.asr.frontend.abs_frontend import AbsFrontend
  from espnet2.asr.postencoder.abs_postencoder import AbsPostEncoder
  from espnet2.asr.preencoder.abs_preencoder import AbsPreEncoder
  from espnet2.asr.specaug.abs_specaug import AbsSpecAug
  from espnet2.enh.loss.wrappers.abs_wrapper import AbsLossWrapper
  from espnet2.layers.abs_normalize import AbsNormalize
  from espnet2.torch_utils.device_funcs import force_gatherable
label_desc: Use image node_id 1 to create a new PITLossWrapper object from inherited base classes: AbsLossWrapper with example: obj = PITLossWrapper(criterion_fn, num_ref)