@Test
    void testValidateUniqueProxyId() throws Exception {
        Settings settings = new Settings();
        Proxy proxy = new Proxy();
        String id = "foo";
        proxy.setId(id);
        proxy.setHost("www.example.com");
        settings.addProxy(proxy);
        settings.addProxy(proxy);

        SimpleProblemCollector problems = new SimpleProblemCollector();
        validator.validate(settings, problems);

    }

    private org.apache.maven.repository.Proxy getProxy(ProxySelector selector, ArtifactRepository repository) {
        if (selector != null) {
            RemoteRepository repo = RepositoryUtils.toRepo(repository);
            org.eclipse.aether.repository.Proxy proxy = selector.getProxy(repo);
            if (proxy != null) {
                org.apache.maven.repository.Proxy p = new org.apache.maven.repository.Proxy();

    @Test
    void testValidateUniqueProxyId() throws Exception {
        Settings settings = new Settings();
        Proxy proxy = new Proxy();
        String id = "foo";
        proxy.setId(id);
        proxy.setHost("www.example.com");
        settings.addProxy(proxy);
        settings.addProxy(proxy);

        SimpleProblemCollector problems = new SimpleProblemCollector();
        validator.validate(settings, problems);

import java.lang.reflect.Proxy


object ProxyCodec : EncodingProducer, Decoding {
    override fun encodingForType(type: Class<*>): Encoding? =
        ProxyEncoding.takeIf { Proxy.isProxyClass(type) }

    override suspend fun ReadContext.decode(): Any {
        val interfaces = readClassArray()
        val handler = read() as InvocationHandler

        return NULLABLE_ANNOTATIONS.any { method.hasAnnotation(it) }
    }

    private static boolean isNullableCtAnnotation(Object ann) {
        if (Proxy.isProxyClass(ann.class)) {
            def typeName = (Proxy.getInvocationHandler(ann) as AnnotationImpl).annotation.typeName
            return NULLABLE_ANNOTATIONS.any { it.name == typeName }
        }
        return false
    }

                    .session((Session) java.lang.reflect.Proxy.newProxyInstance(
                            Session.class.getClassLoader(),
                            new Class[] {Session.class},
                            (Object proxy, Method method, Object[] args) -> {
                                if ("getSystemProperties".equals(method.getName())) {

            SettingsBuilderResult result = builder.build(SettingsBuilderRequest.builder()
                    .session((Session) java.lang.reflect.Proxy.newProxyInstance(
                            Session.class.getClassLoader(),
                            new Class[] {Session.class},
                            (Object proxy, Method method, Object[] args) -> {
                                if ("getSystemProperties".equals(method.getName())) {

        return p::get;
    }

    @SuppressWarnings("unchecked")
    private <T> T createProxy(Key<T> key, Provider<T> unscoped) {
        InvocationHandler dispatcher = (proxy, method, args) -> {
            method.setAccessible(true);
            try {
                return method.invoke(getScopeState().scope(key, unscoped).get(), args);
            } catch (InvocationTargetException e) {

func autoToolchains(ctx context.Context) ([]string, error) {
	var versions *modfetch.Versions
	err := modfetch.TryProxies(func(proxy string) error {
		v, err := modfetch.Lookup(ctx, proxy, "go").Versions(ctx, "")
		if err != nil {
			return err
		}
		versions = v
		return nil
	})
	if err != nil {
		return nil, err
	}
	return versions.List, nil
}

    override fun shouldHandleFeature(feature: InterpretationStepFeature.ResolutionResultPostprocessing) =
        // Use an is-check, as the implementation might be a proxy
        feature is InterpretationStepFeature.ResolutionResultPostprocessing.ConventionApplication

    override fun processResolutionResult(resolutionResult: ResolutionResult): ResolutionResult {