ID { abstract ID normalize();    }
@Test public void testNormalize() { assertEquals(zero, zero.normalize()); assertEquals(one, one.normalize()); assertEquals(zero, zeroZero.normalize()); assertEquals(one, oneOne.normalize()); assertEquals(zeroOne, zeroOne.normalize()); assertEquals(oneZero, oneZero.normalize()); assertEquals(zero, IDs.with(zero, zeroZero).normalize()); assertEquals(zero, IDs.with(zeroZero, zero).normalize()); assertEquals(oneZero, IDs.with(one, zeroZero).normalize()); assertEquals(zeroOne, IDs.with(zeroZero, one).normalize()); assertEquals(one, IDs.with(one, oneOne).normalize()); assertEquals(one, IDs.with(oneOne, one).normalize()); assertEquals(zeroOne, IDs.with(zero, oneOne).normalize()); assertEquals(oneZero, IDs.with(oneOne, zero).normalize()); }