code: def enable(self, http_proxy=None):
          
          self.update(ts_enabled=True, http_proxy=get_proxy(http_proxy))
docs: Enable URL Filtering on the engine. If proxy servers
          are needed, provide a list of HTTPProxy elements.
          
          :param http_proxy: list of proxies for GTI connections
          :type http_proxy: list(str,HttpProxy)