input: 
  def download_subtitles(releases, engines=['DEFAULT_ENGINE'], lang='DEFAULT_LANGUAGE'):
      """ Downloads subtitles for the given releases using the specified engines and language.
  
      >>> download_subtitles(['release1', 'release2'], ['engine1', 'engine2'], 'en')
      []
      >>> download_subtitles(['release1'], ['engine1'], 'en')
      ['/path/to/subtitle.srt']
      """
  
output:     subtitles = []
      for release in releases:
          for engine in engines:
              subtitle_path = f"/path/to/{engine}_{release}_{lang}.srt"
              if os.path.exists(subtitle_path):
                  subtitles.append(subtitle_path)
                  break
      return subtitles