class_docstr: The low-level interface dataset class
  
  Args:
      path_prefix (str): The index (.idx) and data (.bin) prefix
  
      multimodal (bool, optional): Whether the dataset is multimodal. Defaults to False.
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docstr: Initialize the dataset
  
  This method is called by MMapIndexedDataset.__init__ during object creation and by
  MMapIndexedDataset.__setstate__ during un-puckling
  
  Args:
      path_prefix (str): The index (.idx) and data (.bin) prefix
  
      multimodal (bool): Whether the dataset is multimodal
docstr_tok: ["Initialize","the","dataset","This","method","is","called","by","MMapIndexedDataset.__init__","during","object","creation","and","by","MMapIndexedDataset.__setstate__","during","un-puckling","Args",":","path_prefix","(","str",")",":","The","index","(",".idx",")","and","data","(",".bin",")","prefix","multimodal","(","bool",")",":","Whether","the","dataset","is","multimodal"]
code: def initialize(self, path_prefix: str, multimodal: bool) -> None:
      """Initialize the dataset
  
      This method is called by MMapIndexedDataset.__init__ during object creation and by
      MMapIndexedDataset.__setstate__ during un-puckling
  
      Args:
          path_prefix (str): The index (.idx) and data (.bin) prefix
  
          multimodal (bool): Whether the dataset is multimodal
      """
      self.path_prefix = path_prefix
      self.multimodal = multimodal
      self.index = _IndexReader(
          get_idx_path(self.path_prefix), self.multimodal
      )
      self.bin_buffer_mmap = numpy.memmap(
          get_bin_path(self.path_prefix), mode="r", order="C"
      )
      self.bin_buffer = memoryview(self.bin_buffer_mmap)
  
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 2 for calling the MMapIndexedDataset obj's underlying member method code with example usage: obj.initialize(path_prefix, multimodal) without return types