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())

    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #keySet()
    assertSetIsUnmodifiable(multimap.keySet(), sampleKey);
    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #get()
    if (!multimap.isEmpty()) {
      K key = multimap.keySet().iterator().next();
      assertCollectionIsUnmodifiable(multimap.get(key), sampleValue);

            // * if there's a direct dependency, apply the managed dependency to it and discard the managed dep
            // * else keep the managed dep
            managedDependencies.keySet().retainAll(nodes.keySet());

            directDependencies.replaceAll((key, dependency) -> {
                var managedDependency = managedDependencies.get(key);
                if (managedDependency != null) {

            .build();

    ImmutableMap<Range<Integer>, Integer> test = nonEmptyRangeMap.asMapOfRanges();

    for (Range<Integer> range : test.keySet()) {
      SerializableTester.reserializeAndAssert(range);
    }

    SerializableTester.reserializeAndAssert(test.keySet());

    SerializableTester.reserializeAndAssert(nonEmptyRangeMap);
  }

      return emptySet();
    } else {
      return emptyList();
    }
  }

  @Override
  public void clear() {
    keySet().clear();
  }

  @Override
  Set<K> createKeySet() {
    return Sets.filter(unfiltered.keySet(), keyPredicate);
  }

  @Override
  public Collection<V> get(@ParametricNullness K key) {
    if (keyPredicate.apply(key)) {

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_py39.py hl[6:7] *}

    // Tests that serializing a map, its keySet, and values only writes the underlying data once.

    Object[] entries = new Object[2000];
    for (int i = 0; i < entries.length; i++) {
      entries[i] = i;
    }

    ImmutableMap<Integer, Integer> map = RegularImmutableMap.create(entries.length / 2, entries);
    Set<Integer> keySet = map.keySet();
    Collection<Integer> values = map.values();

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

    cache.put(20, 22);
    cache.put(5, 10);

    fakeTicker.advance(501, MILLISECONDS);

    assertThat(cache.asMap().keySet().contains(20)).isTrue();
    assertThat(cache.asMap().keySet().contains(5)).isTrue();
    assertThat(cache.asMap().keySet().contains(10)).isFalse();
  }

  @Test
  public void asMapEntrySet() {
    Cache<Integer, Integer> cache =

* <a href="https://github.com/fastapi/fastapi/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3Aquestion+-label%3Aanswered+" class="external-link" target="_blank">GitHub-Issues</a>

In vielen Fällen kennen Sie möglicherweise bereits die Antwort auf diese Fragen. 🤓

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