if ( listeners != null )
{
for ( Iterator i = listeners.iterator(); i.hasNext(); )
{
DiscoveryListenerDescriptor listenerDescriptor = (DiscoveryListenerDescriptor) i.next();
String role = listenerDescriptor.getRole();
ComponentDiscoveryListener l = (ComponentDiscoveryListener) lookup( role );
componentDiscovererManager.registerComponentDiscoveryListener( l );
}