@GwtCompatible
@NullMarked
public final class EqualsTester {
  private static final int REPETITIONS = 3;

  private final List<List<Object>> equalityGroups = new ArrayList<>();
  private final RelationshipTester.ItemReporter itemReporter;

  /** Constructs an empty EqualsTester instance */
  public EqualsTester() {
    this(/* itemReporter= */ Item::toString);
  }

  EqualsTester(RelationshipTester.ItemReporter itemReporter) {

@GwtCompatible
@NullMarked
public final class EqualsTester {
  private static final int REPETITIONS = 3;

  private final List<List<Object>> equalityGroups = new ArrayList<>();
  private final RelationshipTester.ItemReporter itemReporter;

  /** Constructs an empty EqualsTester instance */
  public EqualsTester() {
    this(/* itemReporter= */ Item::toString);
  }

  EqualsTester(RelationshipTester.ItemReporter itemReporter) {

  public void testEqualsSameContents() {
    new EqualsTester()
        .addEqualityGroup(
            getMultiset(), getSubjectGenerator().create(getSampleElements().toArray()))
        .testEquals();
  }

  @CollectionSize.Require(absent = ZERO)
  public void testNotEqualsEmpty() {
    new EqualsTester()
        .addEqualityGroup(getMultiset())

  }

  /**
   * Test EqualsTester with no equals or not equals objects. This checks proper handling of null,
   * incompatible class and reflexive tests
   */
  public void testTestEqualsEmptyLists() {
    equalsTester.addEqualityGroup(reference);
    equalsTester.testEquals();
  }

  /**
   * Test EqualsTester after populating equalObjects. This checks proper handling of equality and

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractMapTester;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.testing.EqualsTester;
import com.google.common.testing.SerializableTester;
import java.util.Map;
import org.junit.Ignore;

/**
 * Basic serialization test for maps.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.testing.EqualsTester;
import org.junit.Ignore;

/**
 * Testers for {@link SetMultimap#equals(Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

  }

  /**
   * Test EqualsTester with no equals or not equals objects. This checks proper handling of null,
   * incompatible class and reflexive tests
   */
  public void testTestEqualsEmptyLists() {
    equalsTester.addEqualityGroup(reference);
    equalsTester.testEquals();
  }

  /**
   * Test EqualsTester after populating equalObjects. This checks proper handling of equality and

  public void testEqualsTrue() {
    new EqualsTester()
        .addEqualityGroup(multimap(), getSubjectGenerator().create(getSampleElements().toArray()))
        .testEquals();
  }

  public void testEqualsFalse() {
    List<Entry<K, V>> targetEntries = new ArrayList<>(getSampleElements());
    targetEntries.add(mapEntry(k0(), v3()));
    new EqualsTester()
        .addEqualityGroup(multimap())

    assertEquals(null, g.apply(2));
    assertEquals(null, g.apply(null));

    new EqualsTester()
        .addEqualityGroup(f, Functions.constant("correct"))
        .addEqualityGroup(Functions.constant("incorrect"))
        .addEqualityGroup(Functions.toStringFunction())
        .addEqualityGroup(g)
        .testEquals();

    new EqualsTester()
        .addEqualityGroup(g, Functions.<@Nullable Object>constant(null))

  }

  public void testNot_equality() {
    new EqualsTester()
        .addEqualityGroup(Predicates.not(isOdd()), Predicates.not(isOdd()))
        .addEqualityGroup(Predicates.not(TRUE))
        .addEqualityGroup(isOdd())
        .testEquals();
  }

  public void testNot_equalityForNotOfKnownValues() {
    new EqualsTester()
        .addEqualityGroup(TRUE, Predicates.alwaysTrue())