header);
  }

  private static final class Reference<T> {
    private @Nullable T value;

    @Nullable T get() {
      return value;
    }

    void checkAndSet(@Nullable T expected, @Nullable T newValue) {
      if (value != expected) {
        throw new ConcurrentModificationException();
      }
      value = newValue;
    }

    return new TreeRow(rowKey);
  }

  private final class TreeRow extends Row implements SortedMap<C, V> {
    final @Nullable C lowerBound;
    final @Nullable C upperBound;

    TreeRow(R rowKey) {
      this(rowKey, null, null);
    }

    TreeRow(R rowKey, @Nullable C lowerBound, @Nullable C upperBound) {
      super(rowKey);
      this.lowerBound = lowerBound;
      this.upperBound = upperBound;

 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**

        return backingMap.size();
      }

      @Override
      public boolean contains(@Nullable Object key) {
        return containsKey(key);
      }
    };
  }

  // Internal methods (package-visible, but treat as only subclass-visible)

  @Nullable V getIfCached(@Nullable Object key) {
    Entry<K, V> entry = cacheEntry; // store local reference for thread-safety

   */

  static final class Node<K extends @Nullable Object, V extends @Nullable Object>
      extends SimpleEntry<K, V> {
    @Nullable Node<K, V> next; // the next node (with any key)
    @Weak @Nullable Node<K, V> previous; // the previous node (with any key)
    @Nullable Node<K, V> nextSibling; // the next node with the same key
    @Weak @Nullable Node<K, V> previousSibling; // the previous node with the same key

import org.jspecify.annotations.Nullable;

/**
 * Test cases for {@link Tables#transformValues}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public class TablesTransformValuesTest extends AbstractTableTest<Character> {

  private static final Function<@Nullable String, @Nullable Character> FIRST_CHARACTER =
      new Function<@Nullable String, @Nullable Character>() {
        @Override

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A test utility that verifies that your methods and constructors throw {@link
 * NullPointerException} or {@link UnsupportedOperationException} whenever null is passed to a
 * parameter whose declaration or type isn't annotated with an annotation with the simple name
 * {@code Nullable}, {@code CheckForNull}, {@code NullableType}, or {@code NullableDecl}.
 *

  @CanIgnoreReturnValue
  @Override
  public @Nullable V remove(@Nullable Object key) {
    return delegate().remove(key);
  }

  @Override
  public void clear() {
    delegate().clear();
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    return delegate().containsKey(key);
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    return delegate().containsValue(value);

import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterEntries(Multimap, Predicate)}.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
class FilteredEntryMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMultimap<K, V> implements FilteredMultimap<K, V> {

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Used to test listenable future implementations.
 *
 * @author Sven Mawson
 */
@NullUnmarked
public class ListenableFutureTester {

  private final ExecutorService exec;