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);

    /**

	}
	u := *cache.u // copy
	return &u, nil
}

// cache of the current user
var cache struct {
	sync.Once
	u   *User
	err error
}

// Lookup looks up a user by username. If the user cannot be found, the
// returned error is of type [UnknownUserError].
func Lookup(username string) (*User, error) {
	if u, err := Current(); err == nil && u.Username == username {
		return u, err
	}
	return lookupUser(username)
}

apiVersion: release-notes/v2
kind: bug-fix
area: installation
releaseNotes:
  - |

// will attempt to resolve imports in the $GOPATH workspace.
func ForCompiler(fset *token.FileSet, compiler string, lookup Lookup) types.Importer {
	switch compiler {
	case "gc":
		return &gcimports{
			fset:     fset,
			packages: make(map[string]*types.Package),
			lookup:   lookup,
		}

	case "gccgo":
		var inst gccgoimporter.GccgoInstallation

    private final Lookup lookup;
    private final RuntimeInformation runtimeInformation;

    @Inject
    @SuppressWarnings("checkstyle:ParameterNumber")
    public DefaultSessionFactory(
            RepositorySystem repositorySystem,
            MavenRepositorySystem mavenRepositorySystem,
            Lookup lookup,
            RuntimeInformation runtimeInformation) {

        0 * readIndex._
    }

    def "lookup searches the write index then delegates to the read index"() {
        when:
        twoStageIndex.lookup("key")

        then:
        1 * writeIndex.lookup("key") >> null
        1 * readIndex.lookup("key")

        when:
        twoStageIndex.lookup("other")

        then:
        1 * writeIndex.lookup("other") >> Stub(CachedExternalResource)
        0 * readIndex._

    private final Lookup lookup;

    private final TypeRegistry typeRegistry;

    @Inject
    public DefaultPackagingRegistry(Lookup lookup, TypeRegistry typeRegistry, List<PackagingProvider> providers) {
        super(providers);
        this.lookup = lookup;
        this.typeRegistry = typeRegistry;
    }

    @Override
    public Optional<Packaging> lookup(String id) {

        this.lookup = lookup;
    }

    @SuppressWarnings({"rawtypes", "unchecked"})
    @Override
    public void extend(MavenExecutionRequest mavenExecutionRequest) {
        Map<String, PropertyContributor> effectivePropertyContributors = lookup.lookupMap(PropertyContributor.class);
        if (!effectivePropertyContributors.isEmpty()) {

        this.customLifecycles = lifecycles;
        this.lookup = null;
        this.registry = null;
    }

    @Inject
    public DefaultLifecycles(LifecycleRegistry registry, Lookup lookup) {
        this.lookup = lookup;
        this.registry = registry;
    }

    /**
     * Get lifecycle based on phase
     *
     * @param phase
     * @return

        0 * readCache._
    }

    def "lookup searches the write index then delegates to the read index"() {
        when:
        twoStageCache.lookup(key)

        then:
        1 * writeCache.lookup(key) >> null
        1 * readCache.lookup(key)

        when:
        twoStageCache.lookup(key)

        then:
        1 * writeCache.lookup(key) >> Stub(CachedArtifact)
        0 * readCache._
    }