}

    private UpgradeOptions createDefaultOptions() {
        return TestUtils.createDefaultOptions();
    }

    @Nested
    @DisplayName("Applicability")
    class ApplicabilityTests {

        @Test
        @DisplayName("should be applicable when --plugins option is true")
        void shouldBeApplicableWhenPluginsOptionTrue() {
            UpgradeOptions options = mock(UpgradeOptions.class);

    }

    private UpgradeContext createMockContext() {
        return TestUtils.createMockContext();
    }

    @Nested
    @DisplayName("Strategy Execution")
    class StrategyExecutionTests {

        @Test
        @DisplayName("should execute all applicable strategies")
        void shouldExecuteAllApplicableStrategies() throws Exception {
            UpgradeContext context = createMockContext();

    public enum Style { Javadoc, Dsldoc }

    private final Style style;
    private final String displayName;
    private final String urlFragment;

    public LinkMetaData(Style style, String displayName, String urlFragment) {
        this.style = style;
        this.displayName = displayName;
        this.urlFragment = urlFragment;
    }

    public Style getStyle() {
        return style;
    }

    }

    private UpgradeOptions createDefaultOptions() {
        return TestUtils.createDefaultOptions();
    }

    @Nested
    @DisplayName("Applicability")
    class ApplicabilityTests {

        @Test
        @DisplayName("should be applicable when --infer option is true")
        void shouldBeApplicableWhenInferOptionTrue() {
            UpgradeOptions options = mock(UpgradeOptions.class);

/**
 * Unit tests for the {@link UpgradeResult} class.
 * Tests result creation, merging, and status determination.
 */
@DisplayName("UpgradeResult")
class UpgradeResultTest {

    @Nested
    @DisplayName("Result Creation")
    class ResultCreationTests {

        @Test
        @DisplayName("should create empty result")
        void shouldCreateEmptyResult() {
            UpgradeResult result = UpgradeResult.empty();

    }

    private UpgradeContext createMockContext() {
        return TestUtils.createMockContext();
    }

    @Nested
    @DisplayName("Modification Behavior")
    class ModificationBehaviorTests {

        @Test
        @DisplayName("should not save modifications to disk")
        void shouldNotSaveModificationsToDisk() {

    }

    private UpgradeOptions createDefaultOptions() {
        return TestUtils.createDefaultOptions();
    }

    @Nested
    @DisplayName("Applicability")
    class ApplicabilityTests {

        @Test
        @DisplayName("should be applicable when --model option is true")
        void shouldBeApplicableWhenModelOptionTrue() {
            UpgradeOptions options = mock(UpgradeOptions.class);

        applyGoal = new Apply(orchestrator);
        checkGoal = new Check(orchestrator);
    }

    @Nested
    @DisplayName("Model Version Upgrade")
    class ModelVersionUpgradeTests {

        @Test
        @DisplayName("should upgrade from 4.0.0 to 4.1.0 with --model option")
        void shouldUpgradeModelVersionWith41Option() throws Exception {

 * Tests model version detection, validation, upgrade logic, and namespace operations.
 */
@DisplayName("ModelVersionUtils")
class ModelVersionUtilsTest {

    @Nested
    @DisplayName("Model Version Detection")
    class ModelVersionDetectionTests {

        @Test
        @DisplayName("should detect model version from document")
        void shouldDetectModelVersionFromDocument() {

class MonotonicClockTest {

    @Test
    @DisplayName("MonotonicClock singleton instance should always return the same instance")
    void testSingletonInstance() {
        MonotonicClock clock1 = MonotonicClock.get();
        MonotonicClock clock2 = MonotonicClock.get();

        assertSame(clock1, clock2, "Multiple calls to get() should return the same instance");
    }

    @Test
    @DisplayName("MonotonicClock should always use UTC timezone")