final Model model,
            final Path projectDir,
            final ModelBuildingRequest config,
            ModelProblemCollector problems) {
        Map<String, String> modelProperties = model.getProperties();

        ValueSource projectPrefixValueSource;
        ValueSource prefixlessObjectBasedValueSource;
        if (config.getValidationLevel() >= ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_4_0) {

    /**
     * Returns an immutable map of the project properties.
     *
     * @see #setProperty(Project, String, String)
     */
    @Nonnull
    Map<String, String> getProperties(@Nonnull Project project);

    /**
     * Set a given project property.
     *
     * @param project the project to modify
     * @param key they property's key

            }
        } else {
            Properties props = new Properties();
            EnvironmentUtils.addEnvVars(props);
            props.putAll(System.getProperties());
            request.setSystemProperties(props);
        }

        return request;
    }

    @SuppressWarnings("unchecked")
    private List<ArtifactRepository> normalizeToArtifactRepositories(

            try {
                int attrs = f.getAttributes() ^ SmbConstants.ATTR_ARCHIVE ^ SmbConstants.ATTR_HIDDEN ^ SmbConstants.ATTR_READONLY;
                if ( Boolean.parseBoolean(getProperties().getOrDefault("test.skip.hidden", "false")) ) {
                    attrs &= ~SmbConstants.ATTR_HIDDEN;
                }
                f.setAttributes(attrs);
                assertEquals(attrs, f.getAttributes());

        return request.getProfiles().stream()
                .filter(profile -> activeProfileId.contains(profile.getId()))
                .map(ModelBase::getProperties)
                .flatMap(properties -> properties.entrySet().stream())
                .filter(e -> e.getValue() != null)
                .collect(Collectors.toMap(

            final Model model, final File projectDir, final ProjectBuilderConfiguration config) {
        String timestampFormat = DEFAULT_BUILD_TIMESTAMP_FORMAT;

        Properties modelProperties = model.getProperties();
        if (modelProperties != null) {
            timestampFormat = modelProperties.getProperty(BUILD_TIMESTAMP_FORMAT_PROPERTY, timestampFormat);
        }

    @AfterEach
    void tearDown() throws Exception {
        if (origBasedir != null) {
            System.setProperty(MavenCli.MULTIMODULE_PROJECT_DIRECTORY, origBasedir);
        } else {
            System.getProperties().remove(MavenCli.MULTIMODULE_PROJECT_DIRECTORY);
        }
    }

    @Test
    void testPerformProfileActivation() throws ParseException {
        final CommandLineParser parser = new DefaultParser();

    }

    /**
     * Gets the system properties to use for interpolation and profile activation. The system properties are collected
     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    public Properties getSystemProperties() {
        return request.getSystemProperties();
    }

        if (logger.isDebugEnabled()) {
            try {
                ManagementFactory.getRuntimeMXBean().getInputArguments().stream().forEach(s -> logger.debug("Parameter: {}", s));
                System.getProperties().entrySet().stream().forEach(e -> logger.debug("Property: {}={}", e.getKey(), e.getValue()));
                System.getenv().entrySet().forEach(e -> logger.debug("Env: {}={}", e.getKey(), e.getValue()));

*----+------+------+
| <<<*>>> | Java system properties (see {{{https://docs.oracle.com/javase/8/docs/api/java/lang/System.html#getProperties()}JDK reference}}) | <<<$\{user.home\}>>>\
 | | <<<$\{java.home\}>>> |
*----+------+------+
| <<<*>>> | User properties | <<<$\{foo\}>>> |
*----+------+------+
| <<<env.*>>>\