class_docstr: Adds language IDs to an IndexedRawTextDataset
class_docstr_tok: ["Adds","language","IDs","to","an","IndexedRawTextDataset"]
code: def read_data(self, path, dictionary):
      super(IndexedRawTextDatasetWithLangId, self).read_data(
          path, dictionary
      )
      # Postprocess self.tokens_list and self.sizes
      self.sizes += 1
      lang_id_tensor = torch.LongTensor(
          [self.lang_id + MULTILING_DIALECT_ID_OFFSET]
      )
  
      def add_lang_id(tokens):
          if self.prepend_language_id:
              return torch.cat([lang_id_tensor, tokens])
          return torch.cat([tokens, lang_id_tensor])
  
      self.tokens_list = [add_lang_id(t) for t in self.tokens_list]
  
imports: import os
  import shutil
  import tempfile
  from typing import Dict, NamedTuple, Optional
  import numpy
  import torch
  from fairseq import data, tokenizer
  from fvcore.common.file_io import PathManager
  from pytorch_translate import constants
  from pytorch_translate.data import dictionary
label_desc: Use image node_id 2 for calling the IndexedRawTextDatasetWithLangId obj's underlying member method code with example usage: obj.read_data(path, dictionary) and returns: torch, torch