// Properties

    /**
     * Sets 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.
     *
     * @param systemProperties The system properties, may be {@code null}.
     * @return This request, never {@code null}.
     */

    }

    private boolean isEnabled(Project project) {
        Object bwcEnabled = project.getExtensions().getExtraProperties().getProperties().get("bwc_tests_enabled");
        return bwcEnabled == null || (Boolean) bwcEnabled;
    }

    // TODO: implement custom extension that allows us move around of the projects between major versions and still find them

        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(

     *
     * @param project the project for which to get the properties
     *
     * @see #setProperty(Project, String, String)
     */
    @Nonnull
    Map<String, String> getProperties(@Nonnull Project project);

    /**
     * Set a given project property. Properties set through this method are only valid
     * for the current build session and do not modify the underlying project model.
     *

    }

    /**
     * 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();
    }

*----+------+------+
| <<<*>>> | 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.*>>>\

     *
     * @param path
     *            The path to the properties file. Must not be {@literal null} or empty string.
     * @return The properties file.
     */
    public static Properties getProperties(final String path) {
        assertArgumentNotEmpty("path", path);

        final Properties props = new Properties();
        final InputStream is = getResourceAsStream(path);
        try {

            if (sourceDominant) {
                merged.putAll(target.getProperties());
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
            } else {
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
                merged.putAll(target.getProperties());
            }
            target.setProperties(merged);
            target.setLocation(

        Activation defaultActivation = new Activation();

        defaultActivation.setActiveByDefault(true);

        defaultActivated.setActivation(defaultActivation);

        Properties props = System.getProperties();

        ProfileManager profileManager = new DefaultProfileManager(getContainer(), props);

        profileManager.addProfile(notActivated);
        profileManager.addProfile(defaultActivated);

        model.addProperty("key1", "value1");
        model.addProperty("key2", "value2");
        assertEquals(2, model.getProperties().size());

        // This should not throw NullPointerException
        model.getProperties().clear();
        assertEquals(0, model.getProperties().size());
    }