code: def setup_class(cls):
      init_method = "tcp://"
      master_ip = "localhost"
      master_port = "6000"
      init_method += master_ip + ":" + master_port
      torch.distributed.init_process_group(
          backend="gloo", world_size=1, rank=0, init_method=init_method
      )
      parallel_state.initialize_model_parallel(1, 1)
  
imports: import os
  import numpy
  import pytest
  import torch
  from numpy.testing import assert_array_equal
  from omegaconf import OmegaConf
  from scripts.nlp_language_modeling.build_knn_map_index import build_map, dedup
  from nemo.collections.nlp.data.language_modeling.megatron.indexed_retrieval_dataset import KNNIndex, MMapRetrievalIndexedDataset, MMapRetrievalIndexedDatasetBuilder, merge_knn_files
  from nemo.collections.nlp.data.language_modeling.megatron.retro_dataset import RETRODataset
label_desc: Use image node_id 1 for calling the TestRetrievalIndexFiles obj's underlying member method code with example usage: obj.setup_class(cls) without return types