input: 
  def create_flask_app(makeWebhookResult: callable) -> Flask:
      """ Create a Flask app that listens for POST requests on the '/webhook' route. 
      When a request is received, extract the necessary parameters from the request 
      and call the 'makeWebhookResult' function to generate a response. The response 
      should be a JSON object containing a 'speech' field with the text to be spoken 
      by the voice assistant. The app should be started on port 5000 and run in debug mode.
      >>> def mock_makeWebhookResult(req):
      ...     return {"speech": "Test response"}
      >>> app = create_flask_app(mock_makeWebhookResult)
      >>> request = {'result': {'action': 'test'}}
      >>> with app.test_client() as client:
      ...     response = client.post('/webhook', json=request)
      >>> response.json
      {'speech': 'Test response'}
      """
      from flask import Flask, request, make_response
      import json
      import os
  
      app = Flask(__name__)
  
      @app.route('/webhook', methods=['POST'])
      def webhook():
          req = request.get_json(silent=True, force=True)
          res = makeWebhookResult(req)
          res = json.dumps(res, indent=4)
          print(res)
          r = make_response(res)
          r.headers['Content-Type'] = 'application/json'
          return r
  
      if __name__ == '__main__':
          port = int(os.getenv('PORT', 5000))
          print("Starting app on port %d" % port)
          app.run(debug=True, port=port, host='0.0.0.0')
      
      return app
  
output:     from flask import Flask, request, make_response
      import json
      import os
  
      app = Flask(__name__)
  
      @app.route('/webhook', methods=['POST'])
      def webhook():
          req = request.get_json(silent=True, force=True)
          res = makeWebhookResult(req)
          res = json.dumps(res, indent=4)
          print(res)
          r = make_response(res)
          r.headers['Content-Type'] = 'application/json'
          return r
  
      if __name__ == '__main__':
          port = int(os.getenv('PORT', 5000))
          print("Starting app on port %d" % port)
          app.run(debug=True, port=port, host='0.0.0.0')
      
      return app