public void testSize() {
   qi.incubate(a);
   assertEquals(1, qi.size());
   qi.incubate(b);
   assertEquals(2, qi.size());
   qi.hatch(b);
   assertEquals(2, qi.size());
 }
 public void testClear() {
   assertEquals(0, qi.size());
   qi.incubate(a);
   qi.clear();
   assertEquals(0, qi.size());
 }