public synchronized void removeItemListener(ItemListener<E> listener) {
   check(listener);
   itemListenerManager().removeListener(name, listener);
   Packet request = proxyHelper.createRequestPacket(ClusterOperation.REMOVE_LISTENER, null, null);
   Call c = proxyHelper.createCall(request);
   proxyHelper.doCall(c);
 }
 public synchronized void addItemListener(ItemListener<E> listener, boolean includeValue) {
   check(listener);
   Call c = itemListenerManager().createNewAddListenerCall(proxyHelper, includeValue);
   itemListenerManager().registerListener(name, listener, includeValue);
   proxyHelper.doCall(c);
 }