*/
    @Nonnull
    Map<String, String> getSystemProperties();

    /**
     * Returns the properly overlaid map of properties: system + user.
     */
    @Nonnull
    Map<String, String> getEffectiveProperties();

    /**
     * Returns the start time of the session.
     *
     * @return the start time as an Instant object, never {@code null}
     */
    @Nonnull
    Instant getStartTime();

    /**

        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) {
            result.putAll(project.getModel().getProperties());
        }

    public PluginParameterExpressionEvaluatorV4(Session session, Project project, MojoExecution mojoExecution) {
        this.session = session;
        this.mojoExecution = mojoExecution;
        this.properties = session.getEffectiveProperties(project);
        this.project = project;

        Path basedir = null;

        if (project != null) {
            Path projectFile = project.getBasedir();
            basedir = projectFile.toAbsolutePath();