Objects.requireNonNull(profile, "profile cannot be null");

        for (Profile p : getProfiles()) {
            if (p.getId() != null && p.getId().equals(profile.getId())) {
                return this;
            }
        }

        getProfiles().add(profile);

        return this;
    }

    @Override
    public RepositoryCache getRepositoryCache() {

    /**
     * Defines external profiles that may be activated for the given model.
     * Those are external profiles usually defined in {@link org.apache.maven.api.settings.Settings#getProfiles()}.
     */
    @Nonnull
    Collection<Profile> getProfiles();

    /**
     * List of profile ids that have been explicitly activated by the user.
     */
    @Nonnull
    List<String> getActiveProfileIds();

    /**

    }

    public DefaultProjectBuildingRequest(ProjectBuildingRequest request) {
        this();
        setProcessPlugins(request.isProcessPlugins());
        setProfiles(request.getProfiles());
        setActiveProfileIds(request.getActiveProfileIds());
        setInactiveProfileIds(request.getInactiveProfileIds());
        setSystemProperties(request.getSystemProperties());

                                        .childScmDeveloperConnectionInheritAppendPath(null)
                                        .build()
                                : null);
        builder.profiles(prune(model.getProfiles()));

        model = builder.build();
        String modelVersion = new MavenModelVersion().getModelVersion(model);
        if (!ModelBuilder.MODEL_VERSION_4_0_0.equals(modelVersion) && !preserveModelVersion) {

                // do nothing for now
            }
        }

        request.setActiveProfiles(settings.getActiveProfiles());

        for (Profile rawProfile : settings.getProfiles()) {
            request.addProfile(SettingsUtils.convertFromSettingsProfile(rawProfile));

            if (settings.getActiveProfiles().contains(rawProfile.getId())) {

                .flatMap(p -> p.getModel().getDelegate().getProfiles().stream())
                .map(Profile::getId);
        final Stream<String> settingsProfiles =
                session.getSettings().getProfiles().stream().map(org.apache.maven.settings.Profile::getId);
        final Stream<String> superPomProfiles = superPomModels.values().stream()
                .flatMap(p -> p.getProfiles().stream())
                .map(Profile::getId);

                validateStringNotEmpty(problems, "mirrors.mirror.mirrorOf", mirror.getMirrorOf(), mirror.getId());
            }
        }

        List<Profile> profiles = settings.getProfiles();

        if (profiles != null) {
            Set<String> profileIds = new HashSet<>();

            for (Profile profile : profiles) {
                if (!profileIds.add(profile.getId())) {

                new HashSet<>(request.getProfileActivation().getRequiredActiveProfileIds());
        activeProfileId.addAll(request.getProfileActivation().getOptionalActiveProfileIds());

        return request.getProfiles().stream()
                .filter(profile -> activeProfileId.contains(profile.getId()))
                .map(ModelBase::getProperties)
                .flatMap(properties -> properties.entrySet().stream())

     * @since 4.0.0
     */
    MavenExecutionRequest setIgnoreTransitiveRepositories(boolean ignoreTransitiveRepositories);

    // Profiles
    List<Profile> getProfiles();

    MavenExecutionRequest addProfile(Profile profile);

    MavenExecutionRequest setProfiles(List<Profile> profiles);

    /**
     * @deprecated Since Maven 4: use {@link #getProfileActivation()}.
     */
    @Deprecated

     */
    List<Profile> getProfiles();

    /**
     * Sets the external profiles that should be considered for model building.
     *
     * @param profiles The external profiles that should be considered for model building, may be {@code null}.
     * @return This request, never {@code null}.
     */
    ModelBuildingRequest setProfiles(List<Profile> profiles);

    /**