human
Solve the following python programming problem given the following code:
def crossdomain(origin = None, methods = None, headers = None, max_age = 21600, attach_to_all = True, automatic_options = True) : 
    if (methods is not None) : 
        methods = ', '.join (sorted ((x.upper () for x in methods))) 
if ((headers is not None) and (not isinstance (headers, str))) : 
        headers = ', '.join ((x.upper () for x in headers)) 
if (not isinstance (origin, str)) : 
        origin = ', '.join (max_age) 
if isinstance (max_age, timedelta) : 
        max_age = max_age.total_seconds () 
def get_methods() : 
        if (methods is not None) : 
            return methods 
options_resp = current_app.make_default_options_response () 
        return options_resp.headers ['allow'] 
def decorator(f) : 
        def wrapped_function(* args, **kwargs) : 
            if (automatic_options and (request.method == 'OPTIONS')) : 
                resp = current_app.make_default_options_response () 
else : 
                resp = make_response (f (* args, ** kwargs)) 
if ((not attach_to_all) and (request.method != 'OPTIONS')) : 
                return resp 
h = resp.headers 
            h ['Access-Control-Allow-Origin'] = origin 
            h ['Access-Control-Allow-Methods'] = get_methods () 
            h ['Access-Control-Max-Age'] = str (max_age) 
            if (headers is not None) : 
                h ['Access-Control-Allow-Headers'] = headers 
return resp 
f.provide_automatic_options = False 
        return update_wrapper (wrapped_function, f) 
return decorator 

    
    

    Fix the buggy line: origin = ', '.join (max_age)
assistant
#Here is Python code to fix the buggy line: origin = ', '.

origin = ', '.join (origin)