__all__ = [
    'sender_suc_cb',
    'sender_err_cb',
    'recver_suc_cb',
    'recver_err_cb',
    'dummy_cb']


def sender_suc_cb(msg):
    pass


def sender_err_cb(err):
    pass


def recver_suc_cb(msg):
    pass


def recver_err_cb(err):
    pass


def dummy_cb(val):
    pass
