* and listener was registered, null if current state is not equal to required.
* In both cases listener will be notified
*/
public Future<E> notifyWhenStateIsNotEqual(final E state,
final CompletionHandler<E> completionHandler) {
return notifyWhenConditionMatchState(new Condition() {
@Override
public boolean check() {
return state != StateHolder.this.state;
}