code: def add_url (self, url, line=0, column=0, page=0, name=u"", base=None):
          
          if base:
              base_ref = urlutil.url_norm(base)[0]
          else:
              base_ref = None
          url_data = get_url_from(url, self.recursion_level+1, self.aggregate,
              parent_url=self.url, base_ref=base_ref, line=line, column=column,
              page=page, name=name, parent_content_type=self.content_type)
          self.aggregate.urlqueue.put(url_data)
docs: Add new URL to queue.