}

  @LazyInit private transient @Nullable Set<K> keySetView;

  @Override
  public Set<K> keySet() {
    return (keySetView == null) ? keySetView = createKeySet() : keySetView;
  }

  Set<K> createKeySet() {
    return new KeySetView();
  }

  @WeakOuter
  class KeySetView extends Maps.KeySet<K, V> {
    KeySetView() {
      super(CompactHashMap.this);
    }

    @Override

    }
  }

  public void testAsMapGetImplementsSet() {
    for (K key : multimap().keySet()) {
      assertTrue(multimap().asMap().get(key) instanceof Set);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemoveImplementsSet() {
    List<K> keys = new ArrayList<>(multimap().keySet());
    for (K key : keys) {
      resetCollection();

      synchronized (mutex) {
        delegate().clear();
      }
    }

    @Override
    public Set<K> keySet() {
      synchronized (mutex) {
        if (keySet == null) {
          keySet = typePreservingSet(delegate().keySet(), mutex);
        }
        return keySet;
      }
    }

    @Override
    public Collection<V> values() {
      synchronized (mutex) {

      synchronized (mutex) {
        delegate().clear();
      }
    }

    @Override
    public Set<K> keySet() {
      synchronized (mutex) {
        if (keySet == null) {
          keySet = typePreservingSet(delegate().keySet(), mutex);
        }
        return keySet;
      }
    }

    @Override
    public Collection<V> values() {
      synchronized (mutex) {

      String value2 = key2.toString();
      assertThat(cache.getUnchecked(key1)).isSameInstanceAs(value1);
      assertThat(cache.getUnchecked(key2)).isSameInstanceAs(value2);
      assertThat(cache.asMap().keySet()).isEqualTo(ImmutableSet.of(key1, key2));
      assertThat(cache.asMap().values()).containsExactly(value1, value2);
      assertThat(cache.asMap().entrySet())

        return projects;
    }

    public Map<String, String> aliases() {
        return aliases;
    }

    public Stream<MavenProject> projects() {
        return plan.keySet().stream();
    }

    public void addProject(MavenProject project, Map<String, BuildStep> steps) {
        plan.put(project, steps);
    }

    public void addStep(MavenProject project, String name, BuildStep step) {

  }


  public void testKeySet_populated() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      List<Entry<Object, Object>> warmed = warmUp(cache);

      Set<Object> expected = new HashMap<>(cache.asMap()).keySet();
      assertThat(keys).containsExactlyElementsIn(expected);
      assertThat(keys.toArray()).asList().containsExactlyElementsIn(expected);

    assertThrows(UnsupportedOperationException.class, () -> map.tailMap("a").keySet().add("a"));
    assertThrows(UnsupportedOperationException.class, () -> map.headMap("r").keySet().add("a"));
    assertThrows(
        UnsupportedOperationException.class, () -> map.headMap("r").tailMap("m").keySet().add("a"));
  }

  public void testAsMapSortedEmpty() {

    builder.put("c", 4);
    builder.put("a", 2);
    builder.put("b", 6);
    ImmutableListMultimap<String, Integer> multimap = builder.build();
    assertThat(multimap.keySet()).containsExactly("d", "c", "b", "a").inOrder();
    assertThat(multimap.values()).containsExactly(2, 4, 3, 6, 5, 2).inOrder();
    assertThat(multimap.get("a")).containsExactly(5, 2).inOrder();

    }
  }

  public void testAsMapGetImplementsSet() {
    for (K key : multimap().keySet()) {
      assertTrue(multimap().asMap().get(key) instanceof Set);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemoveImplementsSet() {
    List<K> keys = new ArrayList<>(multimap().keySet());
    for (K key : keys) {
      resetCollection();