### Outras funções de utilidade

Si tu función de utilidad es una función normal con `def`, será llamada directamente (como la escribas en tu código), no en un threadpool; si la función es creada con `async def` entonces deberías "await" por esa función cuando la llames en tu código.

---

Nuevamente, estos son detalles muy técnicos que probablemente serían útiles si los buscaste.

 */

package com.google.common.collect;

import java.util.HashMap;

/**
 * GWT emulation of {@link RegularImmutableBiMap}.
 *
 * @author Jared Levy
 * @author Hayward Chan
 */
@SuppressWarnings("serial")
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<Object, Object>();

    }

    public boolean hasRole(final String role) {
        return stream(user.getRoleNames()).get(stream -> stream.anyMatch(s -> s.equals(role)));
    }

    public boolean hasRoles(final String[] acceptedRoles) {
        return stream(user.getRoleNames())
                .get(stream -> stream.anyMatch(s1 -> stream(acceptedRoles).get(s3 -> s3.anyMatch(s2 -> s2.equals(s1)))));
    }

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with

import com.google.common.base.Preconditions;
import java.util.Spliterator;

/**
 * Implementation of {@link ImmutableList} with exactly one element.
 *
 * @author Hayward Chan
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableList<E> extends ImmutableList<E> {

  final transient E element;

  SingletonImmutableList(E element) {

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableMap} with exactly one entry.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {

  final transient K singleKey;
  final transient V singleValue;

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableList} backed by a simple array.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableList<E> extends ImmutableList<E> {
  static final ImmutableList<Object> EMPTY = new RegularImmutableList<>(new Object[0], 0);

import java.util.function.Predicate;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulated version of {@link ImmutableCollection}.
 *
 * @author Jesse Wilson
 */
@SuppressWarnings("serial") // we're overriding default serialization
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  static final int SPLITERATOR_CHARACTERISTICS =

   * ImmutableSortedSet.copyOf(elements)}; if you want a {@code List} you can use its {@code
   * asList()} view.
   *
   * <p><b>Java 8+ users:</b> If you want to convert a {@link java.util.stream.Stream} to a sorted
   * {@code ImmutableList}, use {@code stream.sorted().collect(toImmutableList())}.
   *
   * @throws NullPointerException if any element in the input is null
   * @since 21.0
   */