human
Solve the following python programming problem given the following code:
@ extensionclassmethod (Observable) 
def using(cls, resource_factory, observable_factory) : 
    "Constructs an observable sequence that depends on a resource object,
    whose lifetime is tied to the resulting observable sequence's lifetime.

    1 - res = rx.Observable.using(lambda: AsyncSubject(), lambda: s: s)

    Keyword arguments:
    resource_factory -- Factory function to obtain a resource object.
    observable_factory -- Factory function to obtain an observable sequence
        that depends on the obtained resource.

    Returns an observable sequence whose lifetime controls the lifetime of
    the dependent resource object.
    " 
    def subscribe(observer) : 
        disposable = Disposable.empty () 
        try : 
            resource = resource_factory () 
            if resource : 
                disposable = resource 
source = observable_factory (resource) 
except Exception as exception : 
            d = Observable.throw_exception (exception).subscribe (observer) 
            return CompositeDisposable (d, disposable) 
return CompositeDisposable (source.subscribe (observer), disposable) 
return AnonymousObservable (cls) 

    
    

    Fix the buggy line: return AnonymousObservable (cls)
assistant
#Here is Python program to fix the buggy line: return AnonymousObservable (cls)
.

return AnonymousObservable (subscribe)