human
Solve the following python programming problem given the following code:
def _subscribe_at_pubnub(self) : 
    if (not self.alive ()) : 
        raise Exception ('Subscription is not alive') 
s_key = self._subscription ['deliveryMode'] ['subscriberKey'] 
    self._pubnub = self._pubnub_factory.pubnub (subscribe_key = s_key, ssl_on = False, publish_key = '') 
    def callback(message, channel = '') : 
        self._notify (message) 
def error(message) : 
        print (('ERROR : ' + str (message))) 
def connect(message) : 
        print ('CONNECTED') 
def reconnect(message) : 
        print ('RECONNECTED') 
def disconnect(message) : 
        print ('DISCONNECTED') 
self._pubnub.subscribe (self._subscription ['deliveryMode'] ['address'], callback = disconnect, error = error, connect = connect, reconnect = reconnect, disconnect = disconnect) 

    
    

    Fix the buggy line: self._pubnub.subscribe (self._subscription ['deliveryMode'] ['address'], callback = disconnect, error = error, connect = connect, reconnect = reconnect, disconnect = disconnect)
assistant
#Here is Python code to fix the buggy line: self.

self._pubnub.subscribe (self._subscription ['deliveryMode'] ['address'], callback = callback, error = error, connect = connect, reconnect = reconnect, disconnect = disconnect)