code: def build(self, config, dataset_type):
      self._dataset_type = dataset_type
      self._config = config
      data_folder = os.path.join(get_mmf_root(), self._config.data_dir)
  
      self._download_and_extract_imdb(data_folder)
  
      if self._dataset_type != "train":
          return
  
      self._download_and_extract(
          "vocabs", VISUAL_DIALOG_CONSTS["vocabs"], data_folder
      )
      self._download_and_extract_features(data_folder)
  
file_path: mmf/mmf/datasets/builders/visual_dialog/builder.py
imports: import logging
  import os
  import shutil
  from mmf.common.constants import VISUAL_DIALOG_CONSTS
  from mmf.common.registry import registry
  from mmf.datasets.builders.visual_dialog.dataset import VisualDialogDataset
  from mmf.datasets.builders.visual_genome.builder import VisualGenomeBuilder
  from mmf.utils.download import decompress, download
  from mmf.utils.general import get_mmf_root
label_desc: Use image node_id 3 for calling the VisualDialogBuilder obj's underlying member method code with example usage: obj.build(config, dataset_type) without return types