code: def _get_biased_nnlm(self, dict_file, keyword):
      from .ctc_decoder_utils import BiasedLM, CustomBiasedLM
  
      model = BiasedLM(dict_file, keyword)
      biased_lm = CustomBiasedLM(model, dict_file)
      return biased_lm
  
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 2 for calling the CTCDecoderTest obj's underlying member method code with example usage: obj._get_biased_nnlm(dict_file, keyword) and returns: biased_lm