/** If the listener already exists, it is not added again. */
public void addListener(Listener listener) {
if (listener == null) throw new IllegalArgumentException("listener cannot be null.");
synchronized (listenerLock) {
Listener[] listeners = this.listeners;
int n = listeners.length;
for (int i = 0; i < n; i++) if (listener == listeners[i]) return;
Listener[] newListeners = new Listener[n + 1];
newListeners[0] = listener;
System.arraycopy(listeners, 0, newListeners, 1, n);
this.listeners = newListeners;
}
if (TRACE) trace("kryonet", "Connection listener added: " + listener.getClass().getName());
}
