* rate limit the number of queries we perform.
 *
 * @author Luke Sandberg
 * @since 11.0
 */
@GwtIncompatible
@J2ktIncompatible
public abstract class AbstractScheduledService implements Service {
  private static final LazyLogger logger = new LazyLogger(AbstractScheduledService.class);

  /**
   * A scheduler defines the policy for how the {@link AbstractScheduledService} should run its
   * task.

import jakarta.validation.ConstraintValidator;
import jakarta.validation.ConstraintValidatorContext;

/**
 * Validator implementation for the CronExpression constraint.
 */
public class CronExpressionValidator implements ConstraintValidator<CronExpression, String> {

    /**
     * Default constructor.
     */
    public CronExpressionValidator() {
        // Empty constructor
    }

    @Override

import org.jspecify.annotations.Nullable;

/**
 * An unhashable object to be used in testing as values in our collections.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
public class UnhashableObject implements Comparable<UnhashableObject> {
  private final int value;

  public UnhashableObject(int value) {
    this.value = value;
  }

  @Override
  public boolean equals(@Nullable Object object) {

import org.jspecify.annotations.Nullable;

/** Emulation for InterruptibleTask in GWT. */
abstract class InterruptibleTask<T extends @Nullable Object> implements Runnable {

  @Override
  public void run() {
    T result = null;
    Throwable error = null;
    if (isDone()) {
      return;
    }
    try {
      result = runInterruptibly();

 * @author Zach van Schouwen
 */
@GwtIncompatible
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class SameThreadScheduledExecutorService extends AbstractExecutorService
    implements ListeningScheduledExecutorService {

  private final ListeningExecutorService delegate = newDirectExecutorService();

  @Override
  public void shutdown() {
    delegate.shutdown();
  }

  @Override

 * @author Zach van Schouwen
 */
@GwtIncompatible
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class SameThreadScheduledExecutorService extends AbstractExecutorService
    implements ListeningScheduledExecutorService {

  private final ListeningExecutorService delegate = newDirectExecutorService();

  @Override
  public void shutdown() {
    delegate.shutdown();
  }

  @Override

 * - Uses PBKDF2 for key derivation from master password
 * - Secure wiping of sensitive data
 * - Thread-safe operations
 * - Protection against timing attacks
 */
public class SecureCredentialStorage implements AutoCloseable, Destroyable {

    private static final Logger log = LoggerFactory.getLogger(SecureCredentialStorage.class);

    private static final String ENCRYPTION_ALGORITHM = "AES/GCM/NoPadding";

        builder.put(i, elements[i]);
      }
      return builder.buildOrThrow().values().asList();
    }
  }

  public static class ImmutableMapEntryListGenerator
      implements TestListGenerator<Entry<String, Integer>> {

    @Override
    public SampleElements<Entry<String, Integer>> samples() {
      return new SampleElements<>(
          mapEntry("foo", 5),

    }
    return derivedFeatures;
  }

  private static final class MultimapGetGenerator<K, V>
      extends MultimapTestSuiteBuilder.MultimapGetGenerator<K, V, ListMultimap<K, V>>
      implements TestListGenerator<V> {
    MultimapGetGenerator(
        OneSizeTestContainerGenerator<ListMultimap<K, V>, Entry<K, V>> multimapGenerator) {
      super(multimapGenerator);
    }

    @Override

/**
 * {@link HashFunction} adapter for {@link MessageDigest} instances.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 */
@Immutable
final class MessageDigestHashFunction extends AbstractHashFunction implements Serializable {

  @SuppressWarnings("Immutable") // cloned before each use
  private final MessageDigest prototype;

  private final int bytes;
  private final boolean supportsClone;
  private final String toString;