human
Solve the following python programming problem given the following code:
def middleware(application, global_conf = None) : 
    "
    When applied between a WSGI server and a WSGI application, this
    middleware will check for WSGI compliancy on a number of levels.
    This middleware does not modify the request or response in any
    way, but will throw an AssertionError if anything seems off
    (except for a failure to close the application iterator, which
    will be printed to stderr -- there's no way to throw an exception
    at that point).
    " 
    def lint_app(* args, **kw) : 
        assert (len (args) == 2), 'Two arguments required' 
        assert (not kw), 'No keyword arguments allowed' 
        (environ, start_response) = args 
        check_environ (environ) 
        start_response_started = [] 
        def start_response_wrapper(* args, **kw) : 
            assert ((len (args) == 2) or (len (args) == 3)), ('Invalid number of arguments: %s' % args) 
            assert (not kw), 'No keyword arguments allowed' 
            status = args [0] 
            headers = args [1] 
            if (len (args) == 3) : 
                exc_info = args [2] 
else : 
                exc_info = None 
check_status (status) 
            check_headers (headers) 
            check_content_type (status, headers) 
            check_exc_info (exc_info) 
            start_response_started.append (None) 
            return WriteWrapper (start_response (* args)) 
environ ['wsgi.input'] = InputWrapper (environ ['wsgi.input']) 
        environ ['wsgi.errors'] = ErrorWrapper (environ ['wsgi.errors']) 
        iterator = application (environ, start_response_wrapper) 
        assert ((iterator is not None) and (iterator != False)), 'The application must return an iterator, if only an empty list' 
        check_iterator (iterator) 
        return IteratorWrapper (iterator, start_response_started) 
return application 

    
    

    Fix the buggy line: return application
assistant
#Here is Python program to fix the buggy line: return application
.

return def lint_app(