private void registerAddListener(DN baseDN, ConfigAddListener adaptor)
throws IllegalArgumentException, ConfigException {
ConfigEntry relationEntry = getListenerConfigEntry(baseDN);
if (relationEntry != null) {
relationEntry.registerAddListener(adaptor);
} else {
// The relation entry does not exist yet so register a delayed
// add listener.
ConfigAddListener delayedListener = new DelayedConfigAddListener(baseDN,
adaptor);