@Test
public void testPeek() {

    for (Stamp stamp : stamps) {
        Stamp[] peek = stamp.peek();
        assertIntEquals(2, peek.length);
        assertTrue(peek[0].equals(stamp));
        assertTrue(peek[1].getId().isZero());
        assertTrue(peek[1].getEvent().equals(stamp.getEvent()));
        assertNormalizedStamp(peek[0]);
        assertNormalizedStamp(peek[1]);
    }
}