code: def test_overriden_route():
      app = build_app(reaper_on=False)
  
      @app.route("/")
      def hello_world():
          return "hello world"
  
      with app.test_client() as c:
          resp = c.get("/")
          assert resp.data == b"hello world"
  
imports: import mock
  import pytest
  from dtale.app import build_app
  from tests import ExitStack
label_desc: Use image node_id 1 for calling a global function with example usage: test_overriden_route() and returns: str