def initWithDelegate_(self, cb_obj):
        """
        Arguments:
        - cb_obj: An object that receives callbacks when events occur. This
          object should have:
            - a method '_handle_channeldata' which takes the related channel (a
              IOBluetoothRFCOMMChannel or IOBluetoothL2CAPChannel) and the new
              data (a string) as the arguments.
            - a method '_handle_channelclosed' which takes the related channel
              as the argument.

        If this listener's delegate is passed to the openRFCOMMChannel... or
        openL2CAPChannel... selectors as the delegate, the delegate (and
        therefore this listener) will automatically start receiving events.

        Otherwise, call setDelegate_() on the channel with this listener's
        delegate as the argument to allow this listener to start receiving
        channel events. (This is the only option for server-spawned sockets.)
        """
        self = super(_ChannelEventListener, self).init()
        if cb_obj is None:
            raise TypeError("callback object is None")
        self.__cb_obj = cb_obj
        self.__closenotif = None
        self.__channelDelegate = \
                BBBluetoothChannelDelegate.alloc().initWithDelegate_(self)
        return self
Arguments:
        - cb_obj: An object that receives callbacks when events occur. This
          object should have:
            - a method '_handle_channeldata' which takes the related channel (a
              IOBluetoothRFCOMMChannel or IOBluetoothL2CAPChannel) and the new
              data (a string) as the arguments.
            - a method '_handle_channelclosed' which takes the related channel
              as the argument.

        If this listener's delegate is passed to the openRFCOMMChannel... or
        openL2CAPChannel... selectors as the delegate, the delegate (and
        therefore this listener) will automatically start receiving events.

        Otherwise, call setDelegate_() on the channel with this listener's
        delegate as the argument to allow this listener to start receiving
        channel events. (This is the only option for server-spawned sockets.)