code: def remove_service_listener(self, listener):
          
          with self.__svc_lock:
              try:
                  data = self.__listeners_data.pop(listener)
                  spec_listeners = self.__svc_listeners[data.specification]
                  spec_listeners.remove(data)
                  if not spec_listeners:
                      del self.__svc_listeners[data.specification]
                  return True
              except KeyError:
                  return False
docs: Unregisters a service listener
  
          :param listener: The service listener
          :return: True if the listener has been unregistered