return getProjectSelectors(pa -> pa.optional && pa.active);
    }

    /**
     * @return Required inactive project selectors, never {@code null}.
     */
    public Set<String> getRequiredInactiveProjectSelectors() {
        return getProjectSelectors(pa -> !pa.optional && !pa.active);
    }

    /**
     * @return Optional inactive project selectors, never {@code null}.
     */

        activation = new ProjectActivation();
        performProjectActivation(
                parser.parse(options, new String[] {"-pl", "!test1,-test2,-?test3,!?test4"}), activation);
        assertThat(activation.getRequiredInactiveProjectSelectors(), containsInAnyOrder("test1", "test2"));
        assertThat(activation.getOptionalInactiveProjectSelectors(), containsInAnyOrder("test3", "test4"));

        activation = new ProjectActivation();

        List<MavenProject> result = projects;

        ProjectActivation projectActivation = request.getProjectActivation();
        Set<String> requiredSelectors = projectActivation.getRequiredInactiveProjectSelectors();
        Set<String> optionalSelectors = projectActivation.getOptionalInactiveProjectSelectors();
        if (!requiredSelectors.isEmpty() || !optionalSelectors.isEmpty()) {