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.

    @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) {

     */
    @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

     * 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;
    }

    }

    public boolean isShowErrors() {
        return showErrors;
    }

    public Properties getUserProperties() {
        return userProperties;
    }

    public Properties getSystemProperties() {
        return systemProperties;
    }

    public MavenExecutionRequest getRequest() {
        return request;
    }

    public void setUserProperties(Properties properties) {

        request.setInactiveProfileIds(inactiveProfileIds);

        return this;
    }

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

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

     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The execution properties, never {@code null}.
     */
    Map<String, String> getSystemProperties();

    /**
     * Gets the user properties to use for interpolation and profile activation. The user properties have been

                    if (session != null) {
                        configuration.setSystemProperties(session.getSystemProperties());
                        configuration.setUserProperties(session.getUserProperties());
                    } else {
                        configuration.setSystemProperties(getSystemProperties());
                        configuration.setUserProperties(new Properties());
                    }

        this.userSettingsSource = userSettingsSource;

        return this;
    }

    @Override
    public Properties getSystemProperties() {
        if (systemProperties == null) {
            systemProperties = new Properties();
        }

        return systemProperties;
    }

    @Override

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