{
IdAllocator a = new IdAllocator();
assertEquals(a.allocateId("foo"), "foo");
assertEquals(a.allocateId("foo_0"), "foo_0");
assertEquals(a.allocateId("foo"), "foo_1");
IdAllocator b = a.clone();
// After making a clone, parallel operations should return the same results.
// If anything under the covers was shared, then parallel operations would