a-foundation/src/main/java/com/ajjpj/afoundation/concurrent/ExecutorServiceWrapper.java
@Override public void shutdown () {
        if (poolWithAdmin == null) throw new UnsupportedOperationException ("shutdown only supported for AThreadPoolWithAdmin");
        shutdown.set (AFuture.lift (AThreadPool.SYNC_THREADPOOL, poolWithAdmin.shutdown (AThreadPoolWithAdmin.ShutdownMode.ExecuteSubmitted)));
    }
@Override public void shutdown () {
        if (poolWithAdmin == null) throw new UnsupportedOperationException ("shutdown only supported for AThreadPoolWithAdmin");
        shutdown.set (AFuture.lift (AThreadPool.SYNC_THREADPOOL, poolWithAdmin.shutdown (AThreadPoolWithAdmin.ShutdownMode.ExecuteSubmitted)));
    }
------------------- shutdown handling below this point ---------------------