properties.setProperty("remainingProjects", ":module-a");

        repository.applyResumptionProperties(request, properties);

        assertThat(request.getProjectActivation().getOptionalActiveProjectSelectors(), is(singleton(":module-a")));
    }

    @Test
    void resumeFromPropertyDoesNotOverrideExistingRequestParameters() {
        MavenExecutionRequest request = new DefaultMavenExecutionRequest();

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

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

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

        Set<String> requiredSelectors = projectActivation.getRequiredActiveProjectSelectors();
        Set<String> optionalSelectors = projectActivation.getOptionalActiveProjectSelectors();
        if (!requiredSelectors.isEmpty() || !optionalSelectors.isEmpty()) {
            Set<MavenProject> selectedProjects = new HashSet<>(requiredSelectors.size() + optionalSelectors.size());

        final ProjectActivation projectActivation = request.getProjectActivation();
        final Set<String> allOptionalSelectors = new HashSet<>();
        allOptionalSelectors.addAll(projectActivation.getOptionalActiveProjectSelectors());
        allOptionalSelectors.addAll(projectActivation.getRequiredActiveProjectSelectors());
        // We intentionally ignore the results of this method.