}

  public static <T> EquivalenceTester<T> of(Equivalence<? super T> equivalence) {
    return new EquivalenceTester<>(equivalence);
  }

  /**
   * Adds a group of objects that are supposed to be equivalent to each other and not equivalent to
   * objects in any other equivalence group added to this tester.
   */
  @CanIgnoreReturnValue
  public EquivalenceTester<T> addEquivalenceGroup(T first, T... rest) {

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link EquivalenceTester}.
 *
 * @author Gregory Kick
 */
@GwtCompatible
@NullUnmarked
public class EquivalenceTesterTest extends TestCase {
  private EquivalenceTester<Object> tester;
  private MockEquivalence equivalenceMock;

  @Override
  public void setUp() throws Exception {
    super.setUp();

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link EquivalenceTester}.
 *
 * @author Gregory Kick
 */
@GwtCompatible
@NullUnmarked
public class EquivalenceTesterTest extends TestCase {
  private EquivalenceTester<Object> tester;
  private MockEquivalence equivalenceMock;

  @Override
  public void setUp() throws Exception {
    super.setUp();

   */

  public void testEqualsEquivalent() {
    EquivalenceTester.of(Equivalence.equals())
        .addEquivalenceGroup(new Integer(42_000_000), 42_000_000)
        .addEquivalenceGroup("a")
        .test();
  }

  public void testIdentityEquivalent() {
    EquivalenceTester.of(Equivalence.identity())
        .addEquivalenceGroup(new Integer(42_000_000))

   */

  public void testEqualsEquivalent() {
    EquivalenceTester.of(Equivalence.equals())
        .addEquivalenceGroup(new Integer(42_000_000), 42_000_000)
        .addEquivalenceGroup("a")
        .test();
  }

  public void testIdentityEquivalent() {
    EquivalenceTester.of(Equivalence.identity())
        .addEquivalenceGroup(new Integer(42_000_000))

import java.util.ArrayList;
import java.util.List;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link EqualsTester} and {@link EquivalenceTester} that tests for
 * equivalence classes.
 *
 * @author Gregory Kick
 */
@GwtCompatible
@NullMarked
final class RelationshipTester<T> {
  interface ItemReporter {
    String reportItem(Item<?> item);

import java.util.ArrayList;
import java.util.List;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link EqualsTester} and {@link EquivalenceTester} that tests for
 * equivalence classes.
 *
 * @author Gregory Kick
 */
@GwtCompatible
@NullMarked
final class RelationshipTester<T> {
  interface ItemReporter {
    String reportItem(Item<?> item);