Lease lease1 = new Lease("123", 3000, "foo", null, notifier1, null);
Lease lease2 = new Lease("456", 5000, "bar", null, notifier2, null);
Lease lease3 = new Lease("789", 10000, "foobar", null, notifier3, null);
lease1.startLease();
lease2.startLease();
lease3.startLease();
// when first started, the lease window is lease period X 2
System.out.println("waiting 5 seconds before update.");
Thread.currentThread().sleep(5000);