void doit() {
		DemoData data = new DemoData();
		System.out.println("1 ==> " + getUpdater("value1").getAndSet(data, 10));	// 1 ==> 1
		System.out.println(data.value1);	// 10
		
		System.out.println("3 ==> " + getUpdater("value2").incrementAndGet(data));	// 3 ==> 3
		
		// Class my.atomic.AtomicIntegerFieldUpdaterTest can not access a protected member of class my.atomic.AtomicIntegerFieldUpdaterTest$DemoData using an instance of my.atomic.AtomicIntegerFieldUpdaterTest$DemoData
		//System.out.println("2 ==> " + getUpdater("value3").decrementAndGet(data));
		
		// Class my.atomic.AtomicIntegerFieldUpdaterTest can not access a member of class my.atomic.AtomicIntegerFieldUpdaterTest$DemoData with modifiers "private volatile"
		System.out.println("true ==> " + getUpdater("value4").compareAndSet(data, 4, 5));
	}