code: def check(self, request, user):
          
          us = UserService.objects.get(user=user, name='ServiceWallabag')
  
          params = {'username': us.username,
                    'password': us.password,
                    'client_id': us.client_id,
                    'client_secret': us.client_secret}
          try:
              Wall.get_token(host=us.host, **params)
              return True
          except requests.exceptions.HTTPError as e:
              return e
docs: check if the service is well configured
          :return: Boolean