human
Solve the following python programming problem given the following code:
def create_app(**config) : 
    app = Flask (__name__) 
    app.config.update (config) 
    app.config ['TESTING'] = True 
    htauth = HTAuth (app_index) 
    @ app.route ('/') 
    def app_index() : 
        return 'Hello, World!' 
@ app.route ('/secret') 
    @ authenticated 
    def app_secret() : 
        return (('Hello, ' + g.htauth_user) + '!') 
return app 

    
    

    Fix the buggy line: htauth = HTAuth (app_index)
assistant
#Here is Python code to fix the buggy line: htauth = HTAuth (app_index)
.

htauth = HTAuth (app)