docs: def detect_language(index_page):
      """
      Detect `languages` using `langdetect` library.
  
      Args:
          index_page (str): HTML content of the page you wish to analyze.
  
      Returns:
          obj: One :class:`.SourceString` object.
      """
      dom = dhtmlparser.parseString(index_page)
  
      clean_content = dhtmlparser.removeTags(dom)
  
      lang = None
      try:
          lang = langdetect.detect(clean_content)
      except UnicodeDecodeError:
          lang = langdetect.detect(clean_content.decode("utf-8"))
  
      return SourceString(
          lang,
          source="langdetect"
      )