code: def _lang_token(lang: str):
      return "__{}__".format(lang)
  
imports: import contextlib
  import logging
  import os
  from collections import OrderedDict
  from argparse import ArgumentError
  import torch
  from fairseq import options, utils
  from fairseq.logging import metrics
  from fairseq.data import Dictionary, LanguagePairDataset, RoundRobinZipDatasets, TransformEosLangPairDataset
  from fairseq.models import FairseqMultiModel
  from fairseq.tasks.translation import load_langpair_dataset
  from .None import LegacyFairseqTask, register_task
label_desc: Use image node_id 1 for calling a global function with example usage: _lang_token(lang) and returns: str