/**
 * An immutable {@code Map.Entry}, used both by {@link
 * com.google.common.collect.Maps#immutableEntry(Object, Object)} and by other parts of {@code
 * common.collect} as a superclass.
 */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
class ImmutableEntry<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMapEntry<K, V> implements Serializable {

/**
 * An immutable {@code Map.Entry}, used both by {@link
 * com.google.common.collect.Maps#immutableEntry(Object, Object)} and by other parts of {@code
 * common.collect} as a superclass.
 */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
class ImmutableEntry<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMapEntry<K, V> implements Serializable {

            Maps.<@Nullable String, Integer>immutableEntry(null, 7),
            Maps.<@Nullable String, Integer>immutableEntry(null, 3),
            Maps.<@Nullable String, Integer>immutableEntry(null, 1),
            Maps.<String, @Nullable Integer>immutableEntry("tree", null),
            Maps.immutableEntry("tree", 0),
            Maps.immutableEntry("google", 6),
            Maps.immutableEntry("google", 2))
        .inOrder();
  }

    public SampleElements<Entry<Class, Impl>> samples() {
      return new SampleElements<>(
          immutableEntry((Class) One.class, new Impl(1)),
          immutableEntry((Class) Two.class, new Impl(2)),
          immutableEntry((Class) Three.class, new Impl(3)),
          immutableEntry((Class) Four.class, new Impl(4)),
          immutableEntry((Class) Five.class, new Impl(5)));
    }

    @Override
    @SuppressWarnings("unchecked")

    assertEquals(Maps.immutableEntry("foo", 5), entryIterator.next());
    assertEquals(Maps.immutableEntry("bar", 4), entryIterator.next());
    assertEquals(Maps.immutableEntry("foo", 3), entryIterator.next());
    assertEquals(Maps.immutableEntry("cow", 2), entryIterator.next());
    assertEquals(Maps.immutableEntry("bar", 1), entryIterator.next());

    assertEquals(Maps.immutableEntry("foo", 5), entryIterator.next());
    assertEquals(Maps.immutableEntry("bar", 4), entryIterator.next());
    assertEquals(Maps.immutableEntry("foo", 3), entryIterator.next());
    assertEquals(Maps.immutableEntry("cow", 2), entryIterator.next());
    assertEquals(Maps.immutableEntry("bar", 1), entryIterator.next());

    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);
    assertThat(map.entrySet())
        .containsExactly(
            Maps.immutableEntry("foo", 1),
            Maps.immutableEntry("bar", 2),
            Maps.immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveFirst() {
    BiMap<String, Integer> map = HashBiMap.create();

    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);
    assertThat(map.entrySet())
        .containsExactly(
            Maps.immutableEntry("foo", 1),
            Maps.immutableEntry("bar", 2),
            Maps.immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveFirst() {
    BiMap<String, Integer> map = HashBiMap.create();

    public SampleElements<Entry<Country, String>> samples() {
      return new SampleElements<>(
          Maps.immutableEntry(Country.CANADA, "DOLLAR"),
          Maps.immutableEntry(Country.CHILE, "PESO"),
          Maps.immutableEntry(Country.UK, "POUND"),
          Maps.immutableEntry(Country.JAPAN, "YEN"),
          Maps.immutableEntry(Country.SWITZERLAND, "FRANC"));
    }

    @SuppressWarnings("unchecked")
    @Override

    forwarding.put("b", 2);
    assertEquals(immutableEntry("b", 2), forwarding.lastEntry());
    forwarding.put("c", 3);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.put("a", 1);
    assertEquals(immutableEntry("c", 3), forwarding.lastEntry());
    forwarding.remove("c");
    assertEquals(immutableEntry("b", 2), forwarding.lastEntry());
  }