*/
    @Nullable
    VersionRange getVersionRange();

    /**
     * Returns the recommended version of this constraint, or {@code null} if none.
     * <p>
     * Note: only one, this method or {@link #getVersionRange()} method must return non-{@code null} value.
     */
    @Nullable
    Version getRecommendedVersion();

    /**

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> {

        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;
    }

   */
  public static <E extends @Nullable Object> List<E> asList(
      @ParametricNullness E first, @ParametricNullness E second, E[] rest) {
    return new TwoPlusArrayList<>(first, second, rest);
  }

  /**
   * @see Lists#asList(Object, Object[])
   */
  private static final class OnePlusArrayList<E extends @Nullable Object> extends AbstractList<E>
      implements Serializable, RandomAccess {

import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * Basic implementation of {@code Multiset<E>} backed by an instance of {@code
 * ObjectCountHashMap<E>}.
 *
 * <p>For serialization to work, the subclass must specify explicit {@code readObject} and {@code

  private static final Iterable<@Nullable Integer> iterableNull = Arrays.asList((Integer) null);
  private static final Iterable<@Nullable Integer> iterableNullNull =
      Arrays.asList((Integer) null, null);
  private static final Iterable<@Nullable Integer> iterableNull1 = Arrays.asList(null, 1);
  private static final Iterable<@Nullable Integer> iterable1Null = Arrays.asList(1, null);

import org.jspecify.annotations.Nullable;

/**
 * Derived suite generators for Guava collection interfaces, split out of the suite builders so that
 * they are available to GWT.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public final class DerivedGoogleCollectionGenerators {
  public static class MapGenerator<K extends @Nullable Object, V extends @Nullable Object>

      assertTrue(Thread.holdsLock(mutex));
      return delegate.removeLast();
    }

    @Override
    public @Nullable E pollFirst() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.pollFirst();
    }

    @Override
    public @Nullable E pollLast() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.pollLast();
    }

    @Override

 */
public abstract class LookupInvoker<C extends LookupContext> implements Invoker {
    protected final Lookup protoLookup;

    @Nullable
    protected final Consumer<LookupContext> contextConsumer;

    public LookupInvoker(Lookup protoLookup, @Nullable Consumer<LookupContext> contextConsumer) {
        this.protoLookup = requireNonNull(protoLookup);
        this.contextConsumer = contextConsumer;
    }

  private final boolean hasLowerBound;
  private final @Nullable T lowerEndpoint;
  private final BoundType lowerBoundType;
  private final boolean hasUpperBound;
  private final @Nullable T upperEndpoint;
  private final BoundType upperBoundType;

  private GeneralRange(
      Comparator<? super T> comparator,
      boolean hasLowerBound,
      @Nullable T lowerEndpoint,
      BoundType lowerBoundType,