/**
 * 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 {

    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());
    assertContainsAllOf(keys, k0(), k1());
    assertContainsAllOf(
        keys.entrySet(), Multisets.immutableEntry(k0(), 2), Multisets.immutableEntry(k1(), 1));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testKeysCountAbsentNullKey() {
    assertEquals(0, multimap().keys().count(null));
  }

        .containsExactly(immutableEntry("foo", 1), immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveLast() {
    BiMap<String, Integer> map = HashBiMap.create();
    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);

    map.remove("quux");
    assertThat(map.entrySet())
        .containsExactly(immutableEntry("foo", 1), immutableEntry("bar", 2))

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

    assertTrue(entries.contains(immutableEntry("a", true)));
    assertTrue(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("b", null)));
    assertTrue(
        entries.contains(Maps.<@Nullable String, @Nullable Boolean>immutableEntry(null, null)));

    assertFalse(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("c", null)));

            Entry<Range<Integer>, Integer> expectedEntry = null;
            if (range1.contains(i)) {
              expectedEntry = immutableEntry(range1, 1);
            } else if (range2.contains(i)) {
              expectedEntry = immutableEntry(range2, 2);
            }

            assertEquals(expectedEntry, rangeMap.getEntry(i));
          }
        }
      }
    }
  }

    assertFalse(entries.contains(Maps.immutableEntry("foo", singletonList(1))));
    assertFalse(entries.remove(Maps.immutableEntry("foo", singletonList(1))));
    assertFalse(entries.contains(Maps.immutableEntry("foo", Sets.newLinkedHashSet(asList(1, 2)))));
    assertFalse(entries.remove(Maps.immutableEntry("foo", Sets.newLinkedHashSet(asList(1, 2)))));
    assertFalse(entries.contains(Maps.immutableEntry("foo", singleton(2))));

        new Builder<String, Integer>().put(immutableEntry("one", 1)).build();
    assertEquals(asList(1), multimap.get("one"));
  }

  public void testBuilder_withImmutableEntryAndNullContents() {
    Builder<String, Integer> builder = new Builder<>();
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableEntry("one", (Integer) null)));

    assertTrue(entrySet.contains(immutableEntry(10, 'X')));
    assertTrue(entrySet.contains(immutableEntry(20, 'X')));
    assertFalse(entrySet.contains(immutableEntry(15, 'X')));
    entrySet = row.tailMap(15).entrySet();
    assertFalse(entrySet.contains(immutableEntry(10, 'X')));
    assertTrue(entrySet.contains(immutableEntry(20, 'X')));
    assertFalse(entrySet.contains(immutableEntry(15, 'X')));
  }

            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),
            immutableEntry("tree", 0),
            immutableEntry("google", 6),
            immutableEntry("google", 2))
        .inOrder();
  }