=== "Python 3.10+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial002_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Типы множеств

 */
@GwtCompatible
public class EquivalenceTesterTest extends TestCase {
  private EquivalenceTester<Object> tester;
  private MockEquivalence equivalenceMock;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    this.equivalenceMock = new MockEquivalence();
    this.tester = EquivalenceTester.of(equivalenceMock);
  }

  /** Test null reference yields error */

 */
@GwtCompatible
public class EquivalenceTesterTest extends TestCase {
  private EquivalenceTester<Object> tester;
  private MockEquivalence equivalenceMock;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    this.equivalenceMock = new MockEquivalence();
    this.tester = EquivalenceTester.of(equivalenceMock);
  }

  /** Test null reference yields error */

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testStaticNullPointers() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(CharMatcher.class);
    tester.testAllPublicInstanceMethods(CharMatcher.any());
    tester.testAllPublicInstanceMethods(CharMatcher.anyOf("abc"));
  }

  private static final CharMatcher WHATEVER =
      new CharMatcher() {

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testStaticNullPointers() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(CharMatcher.class);
    tester.testAllPublicInstanceMethods(CharMatcher.any());
    tester.testAllPublicInstanceMethods(CharMatcher.anyOf("abc"));
  }

  private static final CharMatcher WHATEVER =
      new CharMatcher() {

    return !disjoint(a, b);
  }

  private static Method extractMethod(Test test) {
    if (test instanceof AbstractTester) {
      AbstractTester<?> tester = (AbstractTester<?>) test;
      return Helpers.getMethod(tester.getClass(), tester.getTestMethodName());
    } else if (test instanceof TestCase) {
      TestCase testCase = (TestCase) test;
      return Helpers.getMethod(testCase.getClass(), testCase.getName());

  }

  public void testNulls() throws Exception {
    NullPointerTester tester = new NullPointerTester();

    tester.testConstructors(PatternFilenameFilter.class, Visibility.PACKAGE);
    tester.testStaticMethods(PatternFilenameFilter.class, Visibility.PACKAGE); // currently none

    // The reason that we skip this method is discussed in a comment on the method.
    tester.ignore(PatternFilenameFilter.class.getMethod("accept", File.class, String.class));

* Then check if the question (the vast majority are questions) is **clear**.

* In many cases the question asked is about an imaginary solution from the user, but there might be a **better** one. If you can understand the problem and use case better, you might be able to suggest a better **alternative solution**.

* If you can't understand the question, ask for more **details**.

### Reproduce the problem

  }

  public void testNullEqualityGroup() {
    EqualsTester tester = new EqualsTester();
    try {
      tester.addEqualityGroup((Object[]) null);
      fail();
    } catch (NullPointerException e) {
    }
  }

  public void testNullObjectInEqualityGroup() {
    EqualsTester tester = new EqualsTester();
    try {
      tester.addEqualityGroup(1, null, 3);
      fail();

## Deeply nested models

You can define arbitrarily deeply nested models:

=== "Python 3.10+"

    ```Python hl_lines="7  12  18  21  25"
    {!> ../../../docs_src/body_nested_models/tutorial007_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="9  14  20  23  27"
    {!> ../../../docs_src/body_nested_models/tutorial007_py39.py!}
    ```