code: def registerevent(self, event_name, fn_name, *args):
          
          if not isinstance(event_name, str):
              raise ValueError("event_name should be string")
          self._pollEvents._callback[event_name] = [event_name, fn_name, args]
          return self._remote_registerevent(event_name)
docs: Register at-spi event
  
          @param event_name: Event name in at-spi format.
          @type event_name: string
          @param fn_name: Callback function
          @type fn_name: function
          @param *args: arguments to be passed to the callback function
          @type *args: var args
  
          @return: 1 if registration was successful, 0 if not.
          @rtype: integer