// Test getInstance when no instance has been set
        // Should default to System.err
        LogStream instance = LogStream.getInstance();
        assertNotNull(instance);

        // Getting instance again should return the same instance
        LogStream instance2 = LogStream.getInstance();
        assertSame(instance, instance2);
    }

    @Test
    void testSetInstanceAndGetInstance() {

        SmbShareInfo instance3 = new SmbShareInfo("SHARE2", 0, "remark1");
        Object notAShareInfo = new Object();

        assertTrue(instance1.equals(instance2)); // Should be equal based on netName
        assertFalse(instance1.equals(instance3)); // Should not be equal
        assertFalse(instance1.equals(notAShareInfo)); // Should not be equal to other types

      for (Invokable<?, ?> factory : getFactoriesToTest()) {
        Object instance = instantiate(factory);
        if (instance != null
            && packagesToTest.contains(Reflection.getPackageName(instance.getClass()))) {
          try {
            nullPointerTester.testAllPublicInstanceMethods(instance);
          } catch (AssertionError e) {

    // Use reflection to reset the singleton instance between tests
    @BeforeEach
    @AfterEach
    void resetSingleton() {
        try {
            Field instance = SingletonContext.class.getDeclaredField("INSTANCE");
            instance.setAccessible(true);
            instance.set(null, null);
        } catch (NoSuchFieldException | IllegalAccessException e) {

     * <p>
     * If a root package is specified at instance construction, the specified class name is interpreted as a relative name from the root package.
     * </p>
     *
     * @param className the class name
     * @return <code>true</code> if the class file exists in the resources handled by this instance
     */
    boolean isExistClass(final String className);

     * @param index The index name.
     * @return This builder instance.
     */
    public SuggestRequestBuilder setIndex(final String index) {
        request.setIndex(index);
        return this;
    }

    /**
     * Sets the size of results for the request.
     * @param size The size.
     * @return This builder instance.
     */
    public SuggestRequestBuilder setSize(final int size) {

     * @return This builder instance.
     */
    public SuggestSettingsBuilder clusterTimeout(final String timeout) {
        timeoutSettings.setClusterTimeout(timeout);
        return this;
    }

    /**
     * Builds a SuggestSettings instance.
     * @param client The OpenSearch client.
     * @param id The ID.
     * @return A SuggestSettings instance.
     */

         * @param status The status to set.
         * @return This ApiResponse instance.
         */
        public ApiResponse status(final Status status) {
            this.status = status.getId();
            return this;
        }

        /**
         * Returns a new ApiResult instance with this ApiResponse.
         * @return A new ApiResult instance.
         */
        public ApiResult result() {

      @ParametricNullness T instance) {
    return new SupplierOfInstance<>(instance);
  }

  private static final class SupplierOfInstance<T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    @ParametricNullness final T instance;

    SupplierOfInstance(@ParametricNullness T instance) {
      this.instance = instance;
    }

    @Override
    @ParametricNullness
    public T get() {

   * this parameter is marked nullable, this method does nothing.
   *
   * @param instance the instance to invoke {@code method} on, or null if {@code method} is static
   */
  public void testMethodParameter(@Nullable Object instance, Method method, int paramIndex) {
    method.setAccessible(true);
    testParameter(instance, invokable(instance, method), paramIndex, method.getDeclaringClass());
  }

  /**