absl::StrCat("Gradient already exists for op: ", op_name, "."));
  }
  registry_.insert({op_name, gradient_function_factory});
  return absl::OkStatus();
}
absl::Status GradientRegistry::Lookup(
    const ForwardOperation& op,
    std::unique_ptr<GradientFunction>* gradient_function) const {
  auto iter = registry_.find(op.op_name);
  if (iter == registry_.end()) {
    return absl::NotFoundError(

    assertThat(cacheEvents()).containsExactly(CacheMiss::class)

    result = cachedDns.lookup("google.com")
    assertThat(server.takeRequest(1, TimeUnit.MILLISECONDS)).isNull()
    assertThat(result).isEqualTo(listOf(address("157.240.1.18")))

    assertThat(cacheEvents()).containsExactly(CacheHit::class)

    result = cachedDns.lookup("www.google.com")
    assertThat(result).containsExactly(address("157.240.1.18"))

        // Default constructor
    }

    private static final Logger logger = LogManager.getLogger(QueryProcessor.class);

    /**
     * Map of query commands indexed by query class simple names.
     * Used to lookup appropriate command handlers for different query types.
     */
    protected Map<String, QueryCommand> queryCommandMap = new HashMap<>();

    /**
     * List of filters that will be applied during query processing.

    private final Lookup lookup;

    public PlexusContainerCapsule(
            LookupContext context, ClassLoader previousClassLoader, DefaultPlexusContainer plexusContainer) {
        this.previousClassLoader = requireNonNull(previousClassLoader, "previousClassLoader");
        this.plexusContainer = requireNonNull(plexusContainer, "plexusContainer");
        this.lookup = new DefaultLookup(plexusContainer);

    private final Logger logger = LoggerFactory.getLogger(getClass());

    private final Lookup lookup;

    private final DefaultLifecycles defaultLifeCycles;

    @Inject
    public DefaultLifecyclePluginAnalyzer(Lookup lookup, DefaultLifecycles defaultLifeCycles) {
        this.lookup = requireNonNull(lookup);
        this.defaultLifeCycles = requireNonNull(defaultLifeCycles);
    }

            final Object bean = instantiateObject(implType);
            if (null == value) {
                processConfiguration(lookup, bean, loader, configuration, evaluator, listener);
            } else {
                // Use optimized helper for better performance
                new EnhancedCompositeBeanHelper(lookup, loader, evaluator, listener)
                        .setDefault(bean, value, configuration);
            }

   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

  companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

import java.util.Optional;

import org.apache.maven.api.services.Lookup;
import org.apache.maven.api.services.LookupException;

public class SimpleLookup implements Lookup {
    private final List<Object> objects;

    public SimpleLookup(List<Object> objects) {
        this.objects = objects;
    }

    @Override
    public <T> T lookup(Class<T> type) {
        return objects.stream()

                invokerRequest, (EncryptOptions) invokerRequest.options().orElse(null));
    }

    @Override
    protected void lookup(EncryptContext context) throws Exception {
        if (context.goals == null) {
            super.lookup(context);
            context.goals = context.lookup.lookupMap(Goal.class);
        }
    }

    @Override
    protected int execute(EncryptContext context) throws Exception {
        try {

                invokerRequest, (UpgradeOptions) invokerRequest.options().orElse(null));
    }

    @Override
    protected void lookup(UpgradeContext context) throws Exception {
        if (context.goals == null) {
            super.lookup(context);
            context.goals = context.lookup.lookupMap(Goal.class);
        }
    }

    @Override
    protected int execute(UpgradeContext context) throws Exception {
        try {