code: def app(request: SubRequest) -> Iterator[SupersetApp]:
      """
      A fixture that generates a Superset app.
      """
      app = SupersetApp(__name__)
  
      app.config.from_object("superset.config")
      app.config["SQLALCHEMY_DATABASE_URI"] = (
          os.environ.get("SUPERSET__SQLALCHEMY_DATABASE_URI")
          or "sqlite://"
      )
      app.config["WTF_CSRF_ENABLED"] = False
      app.config["PREVENT_UNSAFE_DB_CONNECTIONS"] = False
      app.config["TESTING"] = True
  
      # loop over extra configs passed in by tests
      # and update the app config
      # to override the default configs use:
      #
      # @pytest.mark.parametrize(
      #     "app",
      #     [{"SOME_CONFIG": "SOME_VALUE"}],
      #     indirect=True,
      # )
      # def test_some_test(app_context: None) -> None:
      if request and hasattr(request, "param"):
          for key, val in request.param.items():
              app.config[key] = val
  
      # ``superset.extensions.appbuilder`` is a singleton, and won't rebuild the
      # routes when this fixture is called multiple times; we need to clear the
      # registered views to ensure the initialization can happen more than once.
      appbuilder.baseviews = []
  
      app_initializer = SupersetAppInitializer(app)
      app_initializer.init_app()
  
      # reload base views to ensure error handlers are applied to the app
      with app.app_context():
          import superset.views.base
  
          importlib.reload(superset.views.base)
  
      yield app
  
imports: import functools
  import importlib
  import os
  import unittest.mock
  from collections.abc import Iterator
  from typing import Any, Callable
  from unittest.mock import patch
  import pytest
  from _pytest.fixtures import SubRequest
  from pytest_mock import MockFixture
  from sqlalchemy import create_engine
  from sqlalchemy.orm import sessionmaker
  from sqlalchemy.orm.session import Session
  from superset import security_manager
  from superset.app import SupersetApp
  from superset.common.chart_data import ChartDataResultType
  from superset.common.query_object_factory import QueryObjectFactory
  from superset.extensions import appbuilder, feature_flag_manager
  from superset.initialization import SupersetAppInitializer
label_desc: Use image node_id 3 for calling a global function with example usage: app(request) without return types