public interface Lookup extends Service {
    /**
     * Performs a lookup for given typed component.
     *
     * @param type The component type.
     * @return The component.
     * @param <T> The component type.
     * @throws LookupException if no such component or there is some provisioning related issue.
     */
    @Nonnull
    <T> T lookup(Class<T> type);

    /**

bucket-lookup.png...

    dns[PROXY_A_HOST] = dns.allocate(2)
    val selection = routeSelector.next()
    assertRoute(selection.next(), address, proxyA, dns.lookup(PROXY_A_HOST, 0), PROXY_A_PORT)
    assertRoute(selection.next(), address, proxyA, dns.lookup(PROXY_A_HOST, 1), PROXY_A_PORT)
    assertThat(selection.hasNext()).isFalse()
    assertThat(routeSelector.hasNext()).isFalse()
    dns.assertRequests(PROXY_A_HOST)

@Singleton
@Deprecated(since = "4.0.0")
public class ToolchainManagerFactory {

    private final Lookup lookup;
    private final Logger logger;

    @Inject
    ToolchainManagerFactory(Lookup lookup) {
        this(lookup, null);
    }

    protected ToolchainManagerFactory(Lookup lookup, Logger logger) {
        this.lookup = lookup;
        this.logger = logger;
    }

    @Provides

            }
        }

        private static final Lookup EMPTY_LOOKUP = new Lookup() {
            @Override
            public <T> T lookup(Class<T> type) {
                throw new LookupException("empty lookup");
            }

            @Override
            public <T> T lookup(Class<T> type, String name) {
                throw new LookupException("empty lookup");
            }

            @Override

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()

    assertThat(cacheEvents()).containsExactly("CacheMiss")

    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")

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

 *
 * <p>Cache statistics are incremented according to the following rules:
 *
 * <ul>
 *   <li>When a cache lookup encounters an existing cache entry {@code hitCount} is incremented.
 *   <li>When a cache lookup first encounters a missing cache entry, a new entry is loaded.
 *       <ul>
 *         <li>After successfully loading an entry {@code missCount} and {@code loadSuccessCount}

   */
  @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()

                .build();
    }

    static class WrapperLifecycleRegistry implements LifecycleRegistry {
        @Override
        @Nonnull
        public Optional<Lifecycle> lookup(String id) {
            return getDelegate().lookup(id);
        }

        @Override
        public Iterator<Lifecycle> iterator() {
            return getDelegate().iterator();
        }