input: Write a function to create a command-line interface script that allows users to download subtitles for movies and TV shows by specifying release paths, language, and subtitle site. The script should support commands for downloading, checking existence, testing engines, listing available subtitle sites, and displaying help and version information.
  def download_subtitles_cli(command, releases_path, lang=DEFAULTS['subtitle_language'], engines=[DEFAULTS['subtitle_engine']]):
      if command == 'download':
          download_subtitles(releases_path, engines, lang)
      elif command == 'exist':
          is_subtitles_exist(releases_path, engines, lang)
      elif command == 'test':
          test_engines(engines)
      elif command == 'list':
          for sub_site in SUBTITLE_SITE_LIST.keys():
              sub_dict = SUBTITLE_SITE_LIST.get(sub_site)
              print(sub_dict.get('class_name'))
      elif command == 'help':
          print(__doc__)
      elif command == 'version':
          print('Subtitles Client %s' % __version__)
      else:
          raise ValueError("Invalid command: choose from 'download', 'exist', 'test', 'list', 'help', 'version'")
  
  assert download_subtitles_cli('download', ['Movie1.mp4'], lang='en', engines=['opensubtitles'])
  assert download_subtitles_cli('exist', ['Movie2.mp4'], lang='fr')
  assert download_subtitles_cli('test', [], engines=['opensubtitles'])
  assert download_subtitles_cli('list', [])
  assert download_subtitles_cli('help', [])
  assert download_subtitles_cli('version', [])
output: 
  def download_subtitles_cli(command, releases_path, lang=DEFAULTS['subtitle_language'], engines=[DEFAULTS['subtitle_engine']]):
      if command == 'download':
          download_subtitles(releases_path, engines, lang)
      elif command == 'exist':
          is_subtitles_exist(releases_path, engines, lang)
      elif command == 'test':
          test_engines(engines)
      elif command == 'list':
          for sub_site in SUBTITLE_SITE_LIST.keys():
              sub_dict = SUBTITLE_SITE_LIST.get(sub_site)
              print(sub_dict.get('class_name'))
      elif command == 'help':
          print(__doc__)
      elif command == 'version':
          print('Subtitles Client %s' % __version__)
      else:
          raise ValueError("Invalid command: choose from 'download', 'exist', 'test', 'list', 'help', 'version'")
  