human
Solve the following python programming problem given the following code:
def fancy_error_template_middleware(app) : 
    '
    WGSI middleware for catching errors and rendering the error page.
    ' 
    def application(environ, start_response) : 
        try : 
            return app (environ, start_response) 
except Exception as exc : 
            sio = StringIO () 
            traceback.print_exc (file = sio) 
            sio.seek (0) 
            response = Response (status = 500, body = render_error_page (500, exc, traceback = sio.read ()), content_type = 'text/html') 
            return response (environ, start_response) 
return app 

    
    

    Fix the buggy line: return app
assistant
#Here is Python code to fix the buggy line: return app
.

return def application(