code: def test_create_gateway_client_with_environment_variable(
      gateway, monkeypatch
  ):
      monkeypatch.setenv(MLFLOW_GATEWAY_URI.name, gateway.url)
  
      gateway_client = MlflowGatewayClient()
      assert gateway_client.gateway_uri == gateway.url
      assert isinstance(gateway_client.get_route("completions"), Route)
  
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 12 for calling a global function with example usage: test_create_gateway_client_with_environment_variable(gateway, monkeypatch) without return types