input: 
  def download_subtitles(releases, engines=[DEFAULTS['subtitle_engine']], lang=DEFAULTS['subtitle_language']):
      """ Download subtitles for the given list of releases using the specified subtitle engines.
      >>> download_subtitles(['Movie1.mkv', 'TVShow.S01E01.mkv'], ['OpenSubtitles', 'Addic7ed'], 'en')
      """
  
output:     subtitles = []
      for release in releases:
          for engine in engines:
              subtitle = engine.search(release, lang)
              if subtitle:
                  subtitles.append(subtitle)
                  break
      return subtitles