@Override
    public final Set<Entry<K, V>> entrySet() {
        return delegate.entrySet();
    }
@Test
    public void requireThatSingletonEntryImplementsEquals() {
        Map.Entry<String, String> map = newSingletonMap("foo", "bar").entrySet().iterator().next();
        assertNotEquals(map, null);
        assertNotEquals(map, new Object());
        assertEquals(map, map);
        assertNotEquals(map, newSingletonMap("baz", "cox").entrySet().iterator().next());
        assertNotEquals(map, newSingletonMap("foo", "cox").entrySet().iterator().next());
        assertEquals(map, newSingletonMap("foo", "bar").entrySet().iterator().next());
    }