code: def get_indexed_dataset_infos():
      """Load indexed dataset meta-infos."""
  
      # Load json.
      path = get_indexed_dataset_infos_path()
      with open(path) as f:
          infos = json.load(f)
  
      # Add indexed datasets.
      for info in infos:
          info["dataset"] = MMapIndexedDataset(info["prefix"])
  
      return infos
  
imports: from collections import defaultdict
  import glob
  import json
  import numpy
  import os
  from tqdm import tqdm
  from megatron import get_retro_args, print_rank_0
  from megatron.core.datasets.indexed_dataset import MMapIndexedDataset
  from tools.retro.external_libs import h5py
  from .dataset import DBDataset
label_desc: Use image node_id 4 for calling a global function with example usage: get_indexed_dataset_infos() and returns: infos