class_docstr: Base information retrieval dataset on which other datasets are built.
  
  Args:
      tokenizer: tokenizer
      max_query_length: maximum length of query in tokens
      max_passage_length: maximum length of passage in tokens
class_docstr_tok: ["Base","information","retrieval","dataset","on","which","other","datasets","are","built",".","Args",":","tokenizer",":","tokenizer","max_query_length",":","maximum","length","of","query","in","tokens","max_passage_length",":","maximum","length","of","passage","in","tokens"]
docstr: Internal function which maps passage id to its tokens.
docstr_tok: ["Internal","function","which","maps","passage","id","to","its","tokens","."]
code: def _psgid2tokens(self, psg_id):
      """
      Internal function which maps passage id to its tokens.
      """
      pass
  
imports: import multiprocessing
  import os
  import pickle
  import random
  from typing import Optional
  import numpy
  from torch.utils.data import Dataset
  from nemo.collections.common.tokenizers.tokenizer_spec import TokenizerSpec
label_desc: Use image node_id 9 for calling the BaseInformationRetrievalDataset obj's underlying member method code with example usage: obj._psgid2tokens(psg_id) without return types