code: def test_search_routes_no_routes():
      gateway_client = MlflowGatewayClient(
          gateway_uri="http://localhost:5000"
      )
      resp = mock.Mock(status_code=200)
      resp.json.return_value = {}
      with mock.patch(
          "requests.Session.request", return_value=resp
      ) as request_mock:
          routes = gateway_client.search_routes()
          request_mock.assert_called_once()
          assert routes == []
          assert routes.token is None
  
imports: from unittest import mock
  import pytest
  from requests.exceptions import HTTPError, Timeout
  import mlflow.gateway.utils
  from mlflow.environment_variables import MLFLOW_GATEWAY_URI
  from mlflow.exceptions import InvalidUrlException, MlflowException
  from mlflow.gateway import MlflowGatewayClient, set_gateway_uri
  from mlflow.gateway.config import Route
  from mlflow.gateway.constants import MLFLOW_GATEWAY_SEARCH_ROUTES_PAGE_SIZE
  from mlflow.gateway.utils import resolve_route_url
  from tests.gateway.tools import Gateway, save_yaml
label_desc: Use image node_id 33 for calling a global function with example usage: test_search_routes_no_routes() without return types