* from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    public Properties getSystemProperties() {
        return request.getSystemProperties();
    }

    public Settings getSettings() {
        return settings;
    }

    public List<MavenProject> getProjects() {
        return projects;
    }

    default Builder toBuilder() {
        try {
            return new Builder(
                    getUserProperties(), getSystemProperties(), getStartTime(), getTopDirectory(), getRootDirectory());
        } catch (IllegalStateException e) {
            return new Builder(getUserProperties(), getSystemProperties(), getStartTime(), getTopDirectory(), null);
        }
    }

    /**
     * Returns new builder from scratch.

        String actualOsName = context.getSystemProperties()
                .getOrDefault("os.name", Os.OS_NAME)
                .toLowerCase(Locale.ENGLISH);
        String actualOsArch = context.getSystemProperties()
                .getOrDefault("os.arch", Os.OS_ARCH)
                .toLowerCase(Locale.ENGLISH);
        String actualOsVersion = context.getSystemProperties()
                .getOrDefault("os.version", Os.OS_VERSION)

    protected String getOicClientSecret() {
        return ComponentUtil.getSystemProperties().getProperty(OIC_CLIENT_SECRET, StringUtil.EMPTY);
    }

    /**
     * Gets the OpenID Connect token server URL.
     *
     * @return the token server URL
     */
    protected String getOicTokenServerUrl() {
        return ComponentUtil.getSystemProperties().getProperty(OIC_TOKEN_SERVER_URL, "https://accounts.google.com/o/oauth2/token");

     */
    public static void addSystemProperties(Properties props) {
        props.putAll(getSystemProperties());
    }

    /**
     * Returns a copy of {@link System#getProperties()} in a thread-safe manner.
     *
     * @return {@link System#getProperties()} obtained in a thread-safe manner.
     */
    public static Properties getSystemProperties() {
        return copyProperties(System.getProperties());
    }

    /**

    @Nonnull
    @Override
    public Map<String, String> getSystemProperties() {
        return Collections.unmodifiableMap(new PropertiesAsMap(getMavenSession().getSystemProperties()));
    }

    @Nonnull
    @Override
    public Map<String, String> getEffectiveProperties(@Nullable Project project) {
        HashMap<String, String> result = new HashMap<>(getSystemProperties());
        if (project != null) {

        valueSources.add(new MapBasedValueSource(config.getSystemProperties()));

        valueSources.add(new AbstractValueSource(false) {
            @Override
            public Object getValue(String expression) {
                return config.getSystemProperties().getProperty("env." + expression);
            }
        });

        valueSources.add(modelValueSource2);

        setProfiles(request.getProfiles());
        setActiveProfileIds(request.getActiveProfileIds());
        setInactiveProfileIds(request.getInactiveProfileIds());
        setSystemProperties(request.getSystemProperties());
        setUserProperties(request.getUserProperties());
        setBuildStartTime(request.getBuildStartTime());
        setModelResolver(request.getModelResolver());

     */
    @Nonnull
    List<String> getInactiveProfileIds();

    /**
     * Provides a map of system properties.
     */
    @Nonnull
    Map<String, String> getSystemProperties();

    /**
     * Provides a map of user properties.
     * User properties
     */
    @Nonnull
    Map<String, String> getUserProperties();

    @Nonnull

        request.setInactiveProfileIds(inactiveProfileIds);

        return this;
    }

    @Override
    public Properties getSystemProperties() {
        return request.getSystemProperties();
    }

    @Override
    public FilterModelBuildingRequest setSystemProperties(Properties systemProperties) {
        request.setSystemProperties(systemProperties);