/**
 * Implementation of the {@code equals}, {@code hashCode}, and {@code toString} methods of {@code
 * Entry}.
 *
 * @author Jared Levy
 */
@GwtCompatible
abstract class AbstractMapEntry<K extends @Nullable Object, V extends @Nullable Object>
    implements Entry<K, V> {

  @Override
  @ParametricNullness
  public abstract K getKey();

  @Override
  @ParametricNullness

import java.util.Map.Entry;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@code AbstractMapEntry}.
 *
 * @author Mike Bostock
 */
@GwtCompatible
@NullMarked
public class AbstractMapEntryTest extends TestCase {
  private static final @Nullable String NK = null;

   * null} even for a map which supposedly does not contain null elements, if the key is not present
   * when {@code getValue()} is called.
   */
  private final class EntryForKey extends AbstractMapEntry<K, V> {
    @ParametricNullness final K key;
    int index;

    EntryForKey(int index) {
      // The cast is safe because we call forEntry only for indexes that contain entries.

    ImmutableMap.Builder<String, Integer> builder = new Builder<>();
    StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    ImmutableListMultimap.Builder<String, Integer> builder = new Builder<>();
    StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    ImmutableListMultimap.Builder<String, Integer> builder = new Builder<>();
    StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    ImmutableSetMultimap.Builder<String, Integer> builder = new Builder<>();
    StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    }

    @Override
    public boolean isEmpty() {
      return keyIndex.isEmpty();
    }

    Entry<K, V> getEntry(int index) {
      checkElementIndex(index, size());
      return new AbstractMapEntry<K, V>() {
        @Override
        public K getKey() {
          return ArrayMap.this.getKey(index);
        }

        @Override
        @ParametricNullness
        public V getValue() {

    }

    @Override
    public boolean isEmpty() {
      return keyIndex.isEmpty();
    }

    Entry<K, V> getEntry(int index) {
      checkElementIndex(index, size());
      return new AbstractMapEntry<K, V>() {
        @Override
        public K getKey() {
          return ArrayMap.this.getKey(index);
        }

        @Override
        @ParametricNullness
        public V getValue() {

    }
    return new Itr<Entry<K, V>>() {
      @Override
      Entry<K, V> getOutput(int entry) {
        return new MapEntry(entry);
      }
    };
  }

  final class MapEntry extends AbstractMapEntry<K, V> {
    @ParametricNullness private final K key;

    private int lastKnownIndex;

    MapEntry(int index) {
      this.key = key(index);
      this.lastKnownIndex = index;
    }