import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * Equivalence applied on functional result.
 *
 * @author Bob Lee
 * @since 10.0
 */
@GwtCompatible
final class FunctionalEquivalence<F, T> extends Equivalence<F> implements Serializable {

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

import java.util.Set;

/**
 * An implementation of {@link NetworkConnections} for directed networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
final class DirectedNetworkConnections<N, E> extends AbstractDirectedNetworkConnections<N, E> {

  DirectedNetworkConnections(Map<E, N> inEdgeMap, Map<E, N> outEdgeMap, int selfLoopCount) {
    super(inEdgeMap, outEdgeMap, selfLoopCount);
  }

@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class ListLastIndexOfTester<E> extends AbstractListIndexOfTester<E> {
  @Override
  protected int find(Object o) {
    return getList().lastIndexOf(o);
  }

  @Override
  protected String getMethodName() {

import org.jspecify.annotations.NullMarked;

/**
 * An abstract {@code TestMultisetGenerator} for generating multisets containing enum values.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public abstract class TestEnumMultisetGenerator implements TestMultisetGenerator<AnEnum> {
  @Override
  public SampleElements<AnEnum> samples() {
    return new Enums();
  }

  @Override

@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionForEachTester<E> extends AbstractCollectionTester<E> {
  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testForEachUnknownOrder() {
    List<E> elements = new ArrayList<>();

import static com.google.common.truth.Truth.assertThat;

import com.google.common.annotations.GwtCompatible;
import java.util.SortedMap;
import org.jspecify.annotations.NullMarked;

@GwtCompatible
@NullMarked
public class FilteredSortedMapTest extends AbstractFilteredMapTest {
  @Override
  SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.Iterator;
import org.jspecify.annotations.Nullable;

@GwtCompatible
final class PairwiseEquivalence<E, T extends @Nullable E> extends Equivalence<Iterable<T>>
    implements Serializable {
  final Equivalence<E> elementEquivalence;

  PairwiseEquivalence(Equivalence<E> elementEquivalence) {

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import org.jspecify.annotations.Nullable;

/** Precondition checks useful in collection implementations. */
@GwtCompatible
final class CollectPreconditions {

  static void checkEntryNotNull(@Nullable Object key, @Nullable Object value) {
    if (key == null) {
      throw new NullPointerException("null key in entry: null=" + value);

/**
 * A descending wrapper around an {@code ImmutableSortedMultiset}
 *
 * @author Louis Wasserman
 */
@SuppressWarnings("serial") // uses writeReplace, not default serialization
@GwtIncompatible
final class DescendingImmutableSortedMultiset<E> extends ImmutableSortedMultiset<E> {
  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {

/**
 * Implementation of {@link ImmutableList} with exactly one element.
 *
 * @author Hayward Chan
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableList<E> extends ImmutableList<E> {

  final transient E element;

  SingletonImmutableList(E element) {
    this.element = checkNotNull(element);
  }

  @Override
  public E get(int index) {