package com.baeldung.jdeffered.manager; import org.jdeferred.DeferredManager; import org.jdeferred.impl.DefaultDeferredManager; class SimpleDeferredManagerDemo { public static void initiate() { DeferredManager dm = new DefaultDeferredManager(); dm.when(() -> 1).done(r -> System.out.println("done")).fail(Throwable::printStackTrace); } }