netty shutdown

gistfile1.java

        ioPool.shutdownGracefully().addListener(new GenericFutureListener<Future<?>>() {
            @Override
            public void operationComplete(Future<?> future) throws Exception {
                System.err.println(future.isSuccess());
            }
        });
        
        
        Error:(66, 49) java: incompatible types: <anonymous io.netty.util.concurrent.GenericFutureListener
        <io.netty.util.concurrent.Future<?>>> cannot be converted to io.netty.util.concurrent.GenericFutureListener<? e
        xtends io.netty.util.concurrent.Future<? super capture#1 of ?>>
        
        

And with that: 

        return Observable.from(ioPool.shutdownGracefully()).map(new Func1<Object, Boolean>() {
            @Override
            public Boolean call(Object o) {
                return null;
            }
        });
        
        I get null back for my object...