code: def post(self):
      
      template_values = {
          'back_url': '/showCredentials',
          'back_msg': 'View Credentials',
          'logout_url': users.create_logout_url('/'),
          'user_nickname': users.get_current_user().nickname()
      }
      try:
        UpdateUserCredentials(self.request.get('client_id'),
                              self.request.get('client_secret'),
                              self.request.get('refresh_token'),
                              self.request.get('adwords_manager_cid'),
                              self.request.get('dev_token'))
        self.redirect('/showCredentials')
      except Exception, e:
        template_values['error'] = str(e)
        # Use template to write output to the page.
        path = os.path.join(os.path.dirname(__file__),
                            '../templates/base_template.html')
        self.response.out.write(template.render(path, template_values))
docs: Handle post request.