if (repositories != null) {
            Map<String, Server> serversById = new HashMap<>();

            if (servers != null) {
                for (Server server : servers) {
                    if (!serversById.containsKey(server.getId())) {
                        serversById.put(server.getId(), server);
                    }
                }

import org.apache.maven.api.services.model.*;

/**
 * Handles normalization of a model.
 *
 */
@Named
@Singleton
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

    @Override
    public Model mergeDuplicates(Model model, ModelBuilderRequest request, ModelProblemCollector problems) {
        Model.Builder builder = Model.newBuilder(model);

            // of the form:
            //
            // mvn remote-resources:process
            //
            // From the metadata stored on the server which has been created as part of a standard
            // Maven plugin deployment we will find the right PluginDescriptor from the remote
            // repository.

                Model.Builder builder = Model.newBuilder(model);
                merger.mergeModelBase(builder, model, profile);

                if (profile.getBuild() != null) {
                    Build build = model.getBuild() != null ? model.getBuild() : Build.newInstance();
                    Build.Builder bbuilder = Build.newBuilder(build);
                    merger.mergeBuildBase(bbuilder, build, profile.getBuild());

    public static final String PROXY_HTTP = "HTTP";

    /**
     * Proxy server host
     */
    private String host;

    /**
     * Username used to access the proxy server
     */
    private String userName;

    /**
     * Password associated with the proxy server
     */
    private String password;

    /**
     * Proxy server port
     */
    private int port;

    /**

        request.setPluginGroups(settings.getPluginGroups());

        request.setLocalRepositoryPath(settings.getLocalRepository());

        for (Server server : settings.getServers()) {
            server = server.clone();

            request.addServer(server);
        }

        //  <proxies>
        //    <proxy>
        //      <active>true</active>
        //      <protocol>http</protocol>

    }

    @Test
    void testValidateUniqueServerId() throws Exception {
        Settings settings = new Settings();
        Server server1 = new Server();
        server1.setId("test");
        settings.addServer(server1);
        Server server2 = new Server();
        server2.setId("test");
        settings.addServer(server2);

        SimpleProblemCollector problems = new SimpleProblemCollector();

import org.apache.maven.api.settings.Profile;
import org.apache.maven.api.settings.Repository;
import org.apache.maven.api.settings.RepositoryPolicy;
import org.apache.maven.api.settings.Server;
import org.apache.maven.api.settings.Settings;
import org.apache.maven.settings.v4.SettingsMerger;
import org.apache.maven.settings.v4.SettingsTransformer;
import org.codehaus.plexus.interpolation.EnvarBasedValueSource;

import org.apache.maven.model.io.ModelReader;
import org.apache.maven.project.artifact.ArtifactWithDependencies;
import org.apache.maven.settings.Mirror;
import org.apache.maven.settings.Proxy;
import org.apache.maven.settings.Server;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.sisu.Priority;

/**
 */
@Named
@Singleton
@Priority(10)
@Deprecated
public class TestRepositorySystem implements RepositorySystem {

import org.apache.maven.project.MavenProject;
import org.apache.maven.project.ProjectBuildingRequest;
import org.apache.maven.settings.Mirror;
import org.apache.maven.settings.Proxy;
import org.apache.maven.settings.Server;
import org.apache.maven.settings.Settings;
import org.codehaus.plexus.PlexusContainer;
import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
import org.eclipse.aether.RepositorySystemSession;