class_docstr: Object class to read the index (.idx) file
  
  Args:
      idx_path (str): The path to the index file
  
      multimodal (bool): Whether the dataset is multimodal
class_docstr_tok: ["Object","class","to","read","the","index","(",".idx",")","file","Args",":","idx_path","(","str",")",":","The","path","to","the","index","file","multimodal","(","bool",")",":","Whether","the","dataset","is","multimodal"]
docstr: Return the length of the dataset
  
  Returns:
      int: The length of the dataset
docstr_tok: ["Return","the","length","of","the","dataset","Returns",":","int",":","The","length","of","the","dataset"]
code: def __len__(self) -> int:
      """Return the length of the dataset
  
      Returns:
          int: The length of the dataset
      """
      return self.sequence_count
  
imports: import logging
  import os
  import shutil
  import struct
  import time
  from enum import Enum
  from functools import lru_cache
  from itertools import accumulate
  from types import TracebackType
  from typing import List, Optional, Tuple, Type, Union
  import numpy
  import torch
  from megatron.core.datasets.utils import log_single_rank
label_desc: Use image node_id 3 for calling the _IndexReader obj's underlying member method code with example usage: obj.__len__() and returns: self