code: def set_decoder_langs(self, decoder_langs):
      self.decoder_langs = decoder_langs
  
imports: import os
  from collections import OrderedDict
  from typing import Dict, List, Optional, Tuple
  import numpy
  from fairseq import data, options
  from fairseq.data import ConcatDataset, LanguagePairDataset, NoisingDataset
  from fairseq.data.multi_corpus_sampled_dataset import MultiCorpusSampledDataset
  from fairseq.data.noising import UnsupervisedMTNoising
  from fairseq.tasks import LegacyFairseqTask, register_task
  from pytorch_translate import constants, utils
  from pytorch_translate.data import char_data, data, dictionary, utils, weighted_data
  from pytorch_translate.data.language_pair_upsampling_dataset import LanguagePairUpsamplingDataset
  from pytorch_translate.research.multisource import multisource_data
label_desc: Use image node_id 5 for calling the PytorchTranslateMultilingualTask obj's underlying member method code with example usage: obj.set_decoder_langs(decoder_langs) without return types