Object newValue = new Object();
        assertThat(cache.asMap().replace(entry.getKey(), newValue))
            .isSameInstanceAs(entry.getValue());
        assertThat(cache.asMap().replace(entry.getKey(), newValue, entry.getValue())).isTrue();
        Object newKey = new Object();
        assertThat(cache.asMap().replace(newKey, entry.getValue())).isNull();
        assertThat(cache.asMap().replace(newKey, entry.getValue(), newValue)).isFalse();

        Object newValue = new Object();
        assertThat(cache.asMap().replace(entry.getKey(), newValue))
            .isSameInstanceAs(entry.getValue());
        assertThat(cache.asMap().replace(entry.getKey(), newValue, entry.getValue())).isTrue();
        Object newKey = new Object();
        assertThat(cache.asMap().replace(newKey, entry.getValue())).isNull();
        assertThat(cache.asMap().replace(newKey, entry.getValue(), newValue)).isFalse();

      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

      Set<Object> keys = cache.asMap().keySet();
      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

      try {
        multimap.asMap().get(presentKey).remove(sampleValue);
        fail("asMap().get().remove() succeeded on unmodifiable multimap");
      } catch (UnsupportedOperationException expected) {
      }
      assertMultimapRemainsUnmodified(multimap, originalEntries);

      try {
        multimap.asMap().values().iterator().next().remove(sampleValue);

    map.put("foo", 1);
    map.put("bar", 2);
    Map<String, Collection<Integer>> asMap = Multimaps.forMap(map).asMap();
    assertEquals(singleton(1), asMap.get("foo"));
    assertThat(asMap.get("cow")).isNull();
    assertTrue(asMap.containsKey("foo"));
    assertFalse(asMap.containsKey("cow"));

    Set<Entry<String, Collection<Integer>>> entries = asMap.entrySet();
    assertFalse(entries.contains((Object) 4.5));

    ConcurrentMap<Integer, Integer> asMap = cache.asMap();

    cache.put(10, 100);
    cache.put(2, 52);

    asMap.replace(2, 79);
    asMap.replace(3, 60);

    assertThat(cache.getIfPresent(3)).isNull();
    assertThat(asMap.get(3)).isNull();

    assertThat(cache.getIfPresent(2)).isEqualTo(79);
    assertThat(asMap.get(2)).isEqualTo(79);

    asMap.replace(10, 100, 50);

    return map.values().stream().mapToLong(Long::longValue).sum();
  }

  @LazyInit private transient @Nullable Map<K, Long> asMap;

  /** Returns a live, read-only view of the map backing this {@code AtomicLongMap}. */
  public Map<K, Long> asMap() {
    Map<K, Long> result = asMap;
    return (result == null) ? asMap = createAsMap() : result;
  }

  private Map<K, Long> createAsMap() {
    return Collections.unmodifiableMap(map);

    // 1 won't be cached
    assertThat(cache.getUnchecked(1)).isEqualTo(1);
    assertThat(cache.asMap().keySet()).isEmpty();

    CacheTesting.processPendingNotifications(cache);
    assertThat(removalListener.getCount()).isEqualTo(1);

    // 2 will be cached
    assertThat(cache.getUnchecked(2)).isEqualTo(2);
    assertThat(cache.asMap().keySet()).containsExactly(2);

    CacheTesting.processPendingNotifications(cache);

    assertThat(Iterators.size(cache.asMap().entrySet().iterator())).isEqualTo(1);
    assertThat(Iterators.size(cache.asMap().keySet().iterator())).isEqualTo(1);
    assertThat(Iterators.size(cache.asMap().values().iterator())).isEqualTo(1);

    CacheTesting.expireEntries((LoadingCache<?, ?>) cache, EXPIRING_TIME, ticker);

    for (int i = 0; i < 11; i++) {
      assertThat(cache.asMap().containsKey(KEY_PREFIX + i)).isFalse();
    }