@Test
 public void testSize() {
   assertEquals(0, size());
   Kryo kryo1 = pool.borrow();
   assertEquals(0, size());
   Kryo kryo2 = pool.borrow();
   assertFalse(kryo1 == kryo2);
   pool.release(kryo1);
   assertEquals(1, size());
   pool.release(kryo2);
   assertEquals(2, size());
 }
 @Test
 public void releaseShouldAddKryoToPool() {
   assertEquals(0, size());
   Kryo kryo = pool.borrow();
   pool.release(kryo);
   assertEquals(1, size());
 }
 @Test
 public void getShouldReturnAvailableInstance() {
   Kryo kryo = pool.borrow();
   pool.release(kryo);
   assertTrue(kryo == pool.borrow());
 }