code: def buildImage(opt):
      dpath = os.path.join(opt["datapath"], "COCO-IMG-2015")
      version = "1"
  
      if not build_data.built(dpath, version_string=version):
          print("[building image data: " + dpath + "]")
          if build_data.built(dpath):
              # An older version exists, so remove these outdated files.
              build_data.remove_dir(dpath)
          build_data.make_dir(dpath)
  
          # Download the data.
          for downloadable_file in RESOURCES[:1]:
              downloadable_file.download_file(dpath)
  
          # Mark the data as built.
          build_data.mark_done(dpath, version_string=version)
  
imports: from parlai.core.build_data import DownloadableFile
  import parlai.core.build_data
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: buildImage(opt) without return types