docs: def addUrl(self, url):
          """Add url to binder
          """
  
          if url not in self.urls:
              self.urls.append(url)
  
          root = self.etree
          t_urls = root.find('urls')
  
          if not t_urls:
              t_urls = ctree.SubElement(root, 'urls')
  
          t_url = ctree.SubElement(t_urls, 'url')
          t_url.text = url
  
          return True