code: def build(datapath):
      dpath = os.path.join(datapath, "OpenSubtitles")
      version = "2"
  
      if not build_data.built(dpath, version_string=version):
          print("[building 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              # An older version exists, so remove these outdated files.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:
              downloadable_file.download_file(dpath)
  
          create_fb_format(
              os.path.join(dpath, "OpenSubtitles", "en"), dpath
          )
  
          # Mark the data as built.
          build_data.mark_done(dpath, version_string=version)
      return dpath
  
file_path: ParlAI/parlai/tasks/opensubtitles/build_2009.py
imports: import parlai.core.build_data
  import gzip
  import os
  import re
  from parlai.core.build_data import DownloadableFile
  from parlai.utils.io import PathManager
label_desc: Use image node_id 3 for calling a global function with example usage: build(datapath) and returns: dpath