human
Solve the following python programming problem given the following code:
@ extensionclassmethod (Observable) 
def from_future(cls, future) : 
    'Converts a Future to an Observable sequence

    Keyword Arguments:
    future -- {Future} A Python 3 compatible future.
        https://docs.python.org/3/library/asyncio-task.html#future
        http://www.tornadoweb.org/en/stable/concurrent.html#tornado.concurrent.Future

    Returns {Observable} An Observable sequence which wraps the existing
    future success and failure.
    ' 
    def subscribe(observer) : 
        def done(future) : 
            try : 
                value = future.result () 
except Exception as ex : 
                observer.on_error (ex) 
else : 
                observer.on_next (value) 
                observer.on_completed () 
future.add_done_callback (done) 
        def dispose() : 
            if (future and future.cancel) : 
                future.cancel () 
return dispose 
return (AnonymousObservable (subscribe) if is_future (future) else cls) 

    
    

    Fix the buggy line: return (AnonymousObservable (subscribe) if is_future (future) else cls)
assistant
#Here is Python code to fix the buggy line: return (AnonymousObservable (subscribe) if is_future (future) else cls)
.

return (AnonymousObservable (subscribe) if is_future (future) else future)