private final CountDownLatch returned = new CountDownLatch(1);
    private Object proxy;

    @SuppressWarnings("unchecked") // proxy for a generic class
    <V> Callable<V> waitFor(Callable<V> callable) {
      return waitFor(callable, Callable.class);
    }

    @SuppressWarnings("unchecked") // proxy for a generic class
    <V> ClosingCallable<V> waitFor(ClosingCallable<V> closingCallable) {

    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError =
        threadPool.submit(
            new Callable<@Nullable Void>() {
              @Override
              public @Nullable Void call() throws InterruptedException {
                new Producer(q, 50).call();
                new Interrupter(mainThread).run();
                new Producer(q, 50).call();

# Security Tools

When you need to declare dependencies with OAuth2 scopes you use `Security()`.

But you still need to define what is the dependable, the callable that you pass as a parameter to `Depends()` or `Security()`.

There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.

import static java.util.concurrent.Executors.newFixedThreadPool;

import com.google.common.base.Function;
import com.google.common.primitives.Ints;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ExecutionException;

import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/**
 * Computes a value, possibly asynchronously. For an example usage and more information, see {@link
 * Futures.FutureCombiner#callAsync(AsyncCallable, java.util.concurrent.Executor)}.
 *
 * <p>Much like {@link java.util.concurrent.Callable}, but returning a {@link ListenableFuture}
 * result.
 *
 * @since 20.0
 */

     */
    @FunctionalInterface
    public interface ClosingFunction5<
        V1 extends @Nullable Object,
        V2 extends @Nullable Object,
        V3 extends @Nullable Object,
        V4 extends @Nullable Object,
        V5 extends @Nullable Object,
        U extends @Nullable Object> {
      /**
       * Applies this function to five inputs, or throws an exception if unable to do so.
       *

    public CustomScheduler() {}

    /** A callable class that can reschedule itself using a {@link CustomScheduler}. */
    private final class ReschedulableCallable implements Callable<@Nullable Void> {

      /** The underlying task. */
      private final Runnable wrappedRunnable;

      /** The executor on which this Callable will be scheduled. */
      private final ScheduledExecutorService executor;

        try {
            target.expired();
        } catch (Exception e) {
            // Expected that it may fail due to missing dependencies in test environment
            // but method should be callable
            assertNotNull("Exception should not be null if thrown", e);
        }
    }

    public void test_package_structure() {

            address.firstCalledName();
            address.nextCalledName(mockContext);
            address.toInetAddress();
            address.unwrap(Address.class);
        }, "All Address interface methods should be callable");
    }

    @Test
    @DisplayName("unwrap method should return correct type when supported")
    void testUnwrapMethodContract() throws Exception {
        // Given

    super.setUp();

    fakeTicker = new FakeTicker();
  }

  public void testLoader() throws ExecutionException {
    Cache<Integer, Integer> cache = CacheBuilder.newBuilder().build();

    Callable<Integer> loader =
        new Callable<Integer>() {
          private int i = 0;

          @Override
          public Integer call() throws Exception {
            return ++i;
          }
        };

    cache.put(0, 10);