code: def _get_decoder(
      self, tokens=None, lm=None, use_lexicon=True, **kwargs
  ):
      from torchaudio.models.decoder import ctc_decoder
  
      lexicon_file = (
          get_asset_path("decoder/lexicon.txt") if use_lexicon else None
      )
      if tokens is None:
          tokens = get_asset_path("decoder/tokens.txt")
  
      return ctc_decoder(
          lexicon=lexicon_file,
          tokens=tokens,
          lm=lm,
          **kwargs,
      )
  
imports: import itertools
  import torch
  from parameterized import parameterized
  from torchaudio_unittest.common_utils import get_asset_path, skipIfNoCtcDecoder, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 3 for calling the CTCDecoderTest obj's underlying member method code with example usage: obj._get_decoder(tokens, lm, use_lexicon) and returns: ctc_decoder