title: @GuardedBy , @ThreadSafe ,@NotThreadSafe
body: <p>I see that the above annotations are used extensively in the book JCIP . I think it is really useful because even in the absence of proper documentation it says some things about the synchronization policies . I also see that <a href="http://jetbrains.dzone.com/tips/concurrency-hot-try-jcip" rel="noreferrer">Intellij Idea</a> makes use of these annotations Are they now actually part of the Java language itself ?</p>