}

  private static <K extends @Nullable Object> @Nullable K keyOrNull(@Nullable Node<K, ?> node) {
    return node == null ? null : node.key;
  }

  private static <V extends @Nullable Object> @Nullable V valueOrNull(@Nullable Node<?, V> node) {
    return node == null ? null : node.value;
  }

  private static final class InverseSerializedForm<
          K extends @Nullable Object, V extends @Nullable Object>

     * @return The interpolated string, or null if the input was null.
     */
    @Nullable
    String interpolate(
            @Nullable String val,
            @Nullable UnaryOperator<String> callback,
            @Nullable BinaryOperator<String> postprocessor,
            boolean defaultsToEmpty);

    /**

 * <p>This testing utility is not thread-safe.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
public final class MinimalIterable<E extends @Nullable Object> implements Iterable<E> {
  /** Returns an iterable whose iterator returns the given elements in order. */
  public static <E extends @Nullable Object> MinimalIterable<E> of(E... elements) {
    // Make sure to get an unmodifiable iterator

  }

  private static Iterable<@Nullable Object> iterable(
      @Nullable Object first, @Nullable Object second, @Nullable Object[] rest) {
    checkNotNull(rest);
    return new AbstractList<@Nullable Object>() {
      @Override
      public int size() {
        return rest.length + 2;
      }

      @Override
      public @Nullable Object get(int index) {
        switch (index) {

    int nextSegmentIndex;
    int nextTableIndex;
    @Nullable Segment<K, V> currentSegment;
    @Nullable AtomicReferenceArray<ReferenceEntry<K, V>> currentTable;
    @Nullable ReferenceEntry<K, V> nextEntry;
    @Nullable WriteThroughEntry nextExternal;
    @Nullable WriteThroughEntry lastReturned;

    HashIterator() {
      nextSegmentIndex = segments.length - 1;

import com.google.common.base.Predicate;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(ListMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeyListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends FilteredKeyMultimap<K, V> implements ListMultimap<K, V> {

  static final RegularImmutableBiMap<Object, Object> EMPTY = new RegularImmutableBiMap<>();

  private final transient @Nullable Object keyHashTable;
  @VisibleForTesting final transient @Nullable Object[] alternatingKeysAndValues;
  private final transient int keyOffset; // 0 for K-to-V, 1 for V-to-K
  private final transient int size;
  private final transient RegularImmutableBiMap<V, K> inverse;

    }

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

    @Override
    public @Nullable V get(@Nullable Object key) {
      return getOrDefault(key, null);
    }

    @Override
    public @Nullable V getOrDefault(@Nullable Object key, @Nullable V defaultValue) {
      if (Collections2.safeContains(backingSet(), key)) {

  }

  @Override
  public @Nullable E lower(E element) {
    int index = headIndex(element, false) - 1;
    return (index == -1) ? null : elements.get(index);
  }

  @Override
  public @Nullable E floor(E element) {
    int index = headIndex(element, true) - 1;
    return (index == -1) ? null : elements.get(index);
  }

  @Override
  public @Nullable E ceiling(E element) {

   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.
   * (And even if annotations on local variables were permitted as an optional hint, no annotation
   * would be the right tool for the job here: {@code @Nullable} is the annotation that we're trying