AtomicLong.html">AtomicLong</a></code>, and
 <code><a href="../../../../../reference/java/util/concurrent/atomic/AtomicReference.html">AtomicReference</a></code>
 each provide access and updates to a single variable of the
 corresponding type.  Each class also provides appropriate utility
 methods for that type.  For example, classes <code>AtomicLong</code> and
 <code>AtomicInteger</code> provide atomic increment methods.  One
 application is to generate sequence numbers, as in:

  <pre> <code>class Sequenc