human
Solve the following python programming problem given the following code:
@ classmethod 
def _listen(cls, event_key, propagate = True, **kw) : 
    (target, identifier, fn) = (fn.dispatch_target, event_key.identifier, event_key._listen_fn) 
    def listen(target_cls, * arg) : 
        listen_cls = target () 
        if (propagate and issubclass (target_cls, listen_cls)) : 
            return fn (target_cls, * arg) 
else : 
            if ((not propagate) and (target_cls is listen_cls)) : 
                return fn (target_cls, * arg) 
def remove(ref) : 
        key = event.registry._EventKey (None, identifier, listen, instrumentation._instrumentation_factory) 
        getattr (instrumentation._instrumentation_factory.dispatch, identifier).remove (key) 
target = weakref.ref (target.class_, remove) 
    event_key.with_dispatch_target (instrumentation._instrumentation_factory).with_wrapper (listen).base_listen (** kw) 

    
    

    Fix the buggy line: (target, identifier, fn) = (fn.dispatch_target, event_key.identifier, event_key._listen_fn)
assistant
#Here is Python program to fix the buggy line: (target, identifier, fn) = (fn.

(target, identifier, fn) = (event_key.dispatch_target, event_key.identifier, event_key._listen_fn)