}
  }

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

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

  }


  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);

    }
  }

  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();

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

   */
  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();
  }

  /**

    cache.getUnchecked(one);
    Map<Object, Object> newMap = ImmutableMap.of(one, one);
    assertEquals(newMap, map);
    assertEquals(newMap.entrySet(), map.entrySet());
    assertEquals(newMap.keySet(), map.keySet());
    Set<Object> expectedValues = ImmutableSet.of(one);
    Set<Object> actualValues = ImmutableSet.copyOf(map.values());
    assertEquals(expectedValues, actualValues);
  }

  }

  @Override
  Map<K, Collection<V>> createAsMap() {
    return new AsMap();
  }

  @Override
  Set<K> createKeySet() {
    return asMap().keySet();
  }

  boolean removeEntriesIf(Predicate<? super Entry<K, Collection<V>>> predicate) {
    Iterator<Entry<K, Collection<V>>> entryIterator = unfiltered.asMap().entrySet().iterator();
    boolean changed = false;

 * ListMultimap<String, String> multimap = ArrayListMultimap.create();
 * for (President pres : US_PRESIDENTS_IN_ORDER) {
 *   multimap.put(pres.firstName(), pres.lastName());
 * }
 * for (String firstName : multimap.keySet()) {
 *   List<String> lastNames = multimap.get(firstName);
 *   out.println(firstName + ": " + lastNames);
 * }
 * }
 *
 * ... produces output such as:
 *
 * {@snippet :
 * Zachary: [Taylor]

  }

  @Override
  ImmutableSet<K> createKeySet() {
    return new KeySet<>(this);
  }

  private static final class KeySet<K> extends IndexedImmutableSet<K> {
    private final RegularImmutableMap<K, ?> map;

    KeySet(RegularImmutableMap<K, ?> map) {
      this.map = map;
    }

    @Override
    K get(int index) {

Wenn Sie keinen spezifischen Wert haben wollen, sondern der Parameter einfach optional sein soll, dann setzen Sie den Defaultwert auf `None`.

Aber wenn Sie wollen, dass ein Query-Parameter erforderlich ist, vergeben Sie einfach keinen Defaultwert:

{* ../../docs_src/query_params/tutorial005.py hl[6:7] *}