* @param status The status to set.
         * @return This ApiResponse instance.
         */
        public ApiResponse status(final Status status) {
            this.status = status.getId();
            return this;
        }

        /**
         * Returns a new ApiResult instance with this ApiResponse.
         * @return A new ApiResult instance.
         */
        public ApiResult result() {

Pero queremos poder parametrizar ese contenido fijo.

## Una *instance* "callable"

En Python hay una forma de hacer que una instance de una clase sea un "callable".

No la clase en sí (que ya es un callable), sino una instance de esa clase.

Para hacer eso, declaramos un método `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

      @ParametricNullness T instance) {
    return new SupplierOfInstance<>(instance);
  }

  private static final class SupplierOfInstance<T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    @ParametricNullness final T instance;

    SupplierOfInstance(@ParametricNullness T instance) {
      this.instance = instance;
    }

    @Override
    @ParametricNullness
    public T get() {

            assertNull(e.fillInStackTrace());
            assertEquals(0, e.getStackTrace().length);
        }
    }

    public void test_multipleInstances() {
        // Test that multiple instances maintain their own state
        UserRoleLoginException exception1 = new UserRoleLoginException(RootAction.class);
        UserRoleLoginException exception2 = new UserRoleLoginException(RootAction.class);

   * char[])}.
   *
   * @since 2.0
   */
  public static Comparator<char[]> lexicographicalComparator() {
    return LexicographicalComparator.INSTANCE;
  }

  private enum LexicographicalComparator implements Comparator<char[]> {
    INSTANCE;

    @Override
    public int compare(char[] left, char[] right) {
      int minLength = Math.min(left.length, right.length);

     * <p>
     * If a root package is specified at instance construction, the specified class name is interpreted as a relative name from the root package.
     * </p>
     *
     * @param className the class name
     * @return <code>true</code> if the class file exists in the resources handled by this instance
     */
    boolean isExistClass(final String className);

  public void testAddNullReference() {
    assertThrows(NullPointerException.class, () -> equalsTester.addEqualityGroup((Object) null));
  }

  /** Test equalObjects after adding multiple instances at once with a null */
  public void testAddTwoEqualObjectsAtOnceWithNull() {
    assertThrows(
        NullPointerException.class,
        () -> equalsTester.addEqualityGroup(reference, equalObject1, null));
  }

import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStatsAccumulator}. This tests the stats methods for instances built with
 * {@link PairedStatsAccumulator#add}, and various error cases of that method. For tests of the
 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
@NullUnmarked

            K, V, StrongKeyStrongValueEntry<K, V>, StrongKeyStrongValueSegment<K, V>> {
      private static final Helper<?, ?> INSTANCE = new Helper<>();

      @SuppressWarnings("unchecked")
      static <K, V> Helper<K, V> instance() {
        return (Helper<K, V>) INSTANCE;
      }

      @Override
      public Strength keyStrength() {
        return Strength.STRONG;
      }

      @Override

 * #get(Object, Callable)} or {@link #put(Object, Object)}, and are stored in the cache until either
 * evicted or manually invalidated. The common way to build instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *