*/
  public static Set<Class<?>> allPrimitiveTypes() {
    return PRIMITIVE_TO_WRAPPER_TYPE.keySet();
  }

  /**
   * Returns an immutable set of all nine primitive-wrapper types (including {@link Void}).
   *
   * @since 3.0
   */
  public static Set<Class<?>> allWrapperTypes() {
    return WRAPPER_TO_PRIMITIVE_TYPE.keySet();
  }

  /**

    return new RowSortedMap();
  }

  @WeakOuter
  private final class RowSortedMap extends RowMap implements SortedMap<R, Map<C, V>> {
    @Override
    public SortedSet<R> keySet() {
      return (SortedSet<R>) super.keySet();
    }

    @Override
    SortedSet<R> createKeySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override

  }

  @Override
  SortedMap<K, Collection<V>> backingMap() {
    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override
  Set<K> createKeySet() {
    return createMaybeNavigableKeySet();
  }

///

## Erforderliche Parameter { #required-parameters }

Wenn wir keine weiteren Validierungen oder Metadaten deklarieren müssen, können wir den `q` Query-Parameter erforderlich machen, indem wir einfach keinen Defaultwert deklarieren, wie:

```Python
q: str
```

statt:

```Python
q: str | None = None
```

Aber jetzt deklarieren wir es mit `Query`, zum Beispiel so:

```Python

        assertThat(lru.get("aaa"), is("111"));
        Iterator<String> i = lru.keySet().iterator();
        assertThat(i.next(), is("bbb"));
        assertThat(i.next(), is("ccc"));
        assertThat(i.next(), is("aaa"));
        lru.put("ddd", "444");
        assertThat(lru.size(), is(3));
        assertThat(lru.get("bbb"), is(nullValue()));
        i = lru.keySet().iterator();
        assertThat(i.next(), is("ccc"));

    }

    @Override
    public void remove() {
      iterator.remove();
    }
  }

  Set<K> keySet;

  @Override
  public Set<K> keySet() {
    // does not impact recency ordering
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet(this));
  }

  Collection<V> values;

  @Override
  public Collection<V> values() {

    return new RowSortedMap();
  }

  @WeakOuter
  private final class RowSortedMap extends RowMap implements SortedMap<R, Map<C, V>> {
    @Override
    public SortedSet<R> keySet() {
      return (SortedSet<R>) super.keySet();
    }

    @Override
    SortedSet<R> createKeySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override

  }

  @Override
  SortedMap<K, Collection<V>> backingMap() {
    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override
  Set<K> createKeySet() {
    return createMaybeNavigableKeySet();
  }

    assertContainsAllOf(
        keys.entrySet(), Multisets.immutableEntry((K) null, 2), Multisets.immutableEntry(k1(), 1));
  }

  public void testKeysElementSet() {
    assertEquals(multimap().keySet(), multimap().keys().elementSet());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeysRemove() {
    int original = multimap().keys().remove(k0(), 1);

    for (K key : multimap().keySet()) {
      SortedSet<V> valueSet = (SortedSet<V>) multimap().asMap().get(key);
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

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