code: def find_links (url_data, callback, tags):
      
      # construct parser object
      handler = linkparse.LinkFinder(callback, tags)
      parser = htmlsax.parser(handler)
      if url_data.charset:
          parser.encoding = url_data.charset
      handler.parser = parser
      # parse
      try:
          parser.feed(url_data.get_content())
          parser.flush()
      except linkparse.StopParse as msg:
          log.debug(LOG_CHECK, "Stopped parsing: %s", msg)
          pass
      # break cyclic dependencies
      handler.parser = None
      parser.handler = None
docs: Parse into content and search for URLs to check.
      Found URLs are added to the URL queue.