code: def test_get_route_accepts_unknown_route_type():
      set_gateway_uri("http://localhost:5000")
      mock_resp = mock.Mock(status_code=200)
      mock_resp.json.return_value = {
          "name": "chat",
          "route_type": "llm/v1/unknown",
          "model": {"name": "gpt4", "provider": "openai"},
          "route_url": "http://localhost:5000/gateway/chat/invocations",
      }
      with mock.patch(
          "requests.Session.request", return_value=mock_resp
      ) as mock_request:
          route = get_route("chat")
          mock_request.assert_called_once()
          assert route.dict() == mock_resp.json()
  
imports: from unittest import mock
  import pytest
  from requests.exceptions import HTTPError
  import mlflow.gateway.utils
  from mlflow.environment_variables import MLFLOW_GATEWAY_URI
  from mlflow.exceptions import MlflowException
  from mlflow.gateway import create_route, delete_route, get_gateway_uri, get_limits, get_route, query, search_routes, set_gateway_uri, set_limits
  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 21 for calling a global function with example usage: test_get_route_accepts_unknown_route_type() without return types