code: def fetch(self, conf):
          
          url = conf['url']
          # If Firefox is broken, it will raise here, causing kibitzr restart:
          self.driver.set_window_size(1366, 800)
          self.driver.implicitly_wait(2)
          self.driver.get(url)
          try:
              self._run_automation(conf)
              html = self._get_html()
          except:
              logger.exception(
                  "Exception occurred while fetching"
              )
              return False, traceback.format_exc()
          finally:
              self._close_tab()
          return True, html
docs: 1. Fetch URL
          2. Run automation.
          3. Return HTML.
          4. Close the tab.