human
Solve the following python programming problem given the following code:
@ extensionclassmethod (Observable) 
def catch_exception(cls, * args) : 
    'Continues an observable sequence that is terminated by an
    exception with the next observable sequence.

    1 - res = Observable.catch_exception(xs, ys, zs)
    2 - res = Observable.catch_exception([xs, ys, zs])

    Returns an observable sequence containing elements from consecutive
    source sequences until a source sequence terminates successfully.
    ' 
    if (isinstance (args [0], list) or isinstance (args [0], Enumerable)) : 
        sources = args [0] 
else : 
        sources = list (cls) 
def subscribe(observer) : 
        e = iter (sources) 
        is_disposed = [False] 
        last_exception = [None] 
        subscription = SerialDisposable () 
        def action(action1, state = None) : 
            def on_error(exn) : 
                last_exception [0] = exn 
                action1 () 
if is_disposed [0] : 
                return 
try : 
                current = next (e) 
except StopIteration : 
                if last_exception [0] : 
                    observer.on_error (last_exception [0]) 
else : 
                    observer.on_completed () 
except Exception as ex : 
                observer.on_error (ex) 
else : 
                d = SingleAssignmentDisposable () 
                subscription.disposable = d 
                d.disposable = current.subscribe (observer.on_next, on_error, observer.on_completed) 
cancelable = immediate_scheduler.schedule_recursive (action) 
        def dispose() : 
            is_disposed [0] = True 
return CompositeDisposable (subscription, cancelable, Disposable (dispose)) 
return AnonymousObservable (subscribe) 

    
    

    Fix the buggy line: sources = list (cls)
assistant
#Here is Python code to fix the buggy line: sources = list (cls)
.

sources = list (args)