code: def test_openapi_schema():
      response = client.get("/openapi.json")
      assert response.status_code == 200
      assert response.json() == {
          "openapi": "3.1.0",
          "info": {"title": "FastAPI", "version": "0.1.0"},
          "servers": [
              {
                  "url": IsOneOf(
                      "https://stag.example.com/",
                      # TODO: remove when deprecating Pydantic v1
                      "https://stag.example.com",
                  ),
                  "description": "Staging environment",
              },
              {
                  "url": IsOneOf(
                      "https://prod.example.com/",
                      # TODO: remove when deprecating Pydantic v1
                      "https://prod.example.com",
                  ),
                  "description": "Production environment",
              },
          ],
          "paths": {
              "/app": {
                  "get": {
                      "summary": "Read Main",
                      "operationId": "read_main_app_get",
                      "responses": {
                          "200": {
                              "description": "Successful Response",
                              "content": {
                                  "application/json": {"schema": {}}
                              },
                          }
                      },
                  }
              }
          },
      }
  
imports: from dirty_equals import IsOneOf
  from fastapi.testclient import TestClient
  from docs_src.behind_a_proxy.tutorial004 import app
label_desc: Use image node_id 2 for calling a global function with example usage: test_openapi_schema() without return types