*
   * @since 20.0 (varargs overload since 2.0)
   */
  @CanIgnoreReturnValue
  public static <T> T checkNotNull(
      @Nullable T reference,
      String errorMessageTemplate,
      @Nullable Object p1,
      @Nullable Object p2,
      @Nullable Object p3,
      @Nullable Object p4) {
    if (reference == null) {
      throw new NullPointerException(Platform.lenientFormat(errorMessageTemplate, p1, p2, p3, p4));

          null, null, (Entry<Object, Object>[]) ImmutableMap.EMPTY_ENTRY_ARRAY, 0, 0);

  static final double MAX_LOAD_FACTOR = 1.2;

  private final transient @Nullable ImmutableMapEntry<K, V> @Nullable [] keyTable;
  private final transient @Nullable ImmutableMapEntry<K, V> @Nullable [] valueTable;
  @VisibleForTesting final transient Entry<K, V>[] entries;
  private final transient int mask;
  private final transient int hashCode;

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> {

    return size() == 0;
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    return get(key) != null;
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    return values().contains(value);
  }

  // Overriding to mark it Nullable
  @Override
  public abstract @Nullable V get(@Nullable Object key);

  /**
   * {@inheritDoc}
   *
   * <p>See <a

  }

  static boolean patternCompilerIsPcreLike() {
    throw new UnsupportedOperationException();
  }

  static String lenientFormat(@Nullable String template, @Nullable Object @Nullable ... args) {
    return Strings.lenientFormat(template, args);
  }

  static String stringValueOf(@Nullable Object o) {
    return String.valueOf(o);
  }

  private Platform() {}

    runConcurrentTest(
        numberOfThreads,
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {
            long unused = ticker.read();
            return null;
          }
        });

    assertEquals(incrementByNanos * numberOfThreads, ticker.read());
  }

  /** Runs {@code callable} concurrently {@code numberOfThreads} times. */

   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {
    return new SupplierComposition<>(function, supplier);
  }

  private static final class SupplierComposition<
          F extends @Nullable Object, T extends @Nullable Object>
      implements Supplier<T>, Serializable {

      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

  @Override
  public <T extends B> @Nullable T putInstance(
      Class<@NonNull T> type, @ParametricNullness T value) {
    return cast(type, put(type, value));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return cast(type, get(type));
  }

  @CanIgnoreReturnValue
  private static <T> @Nullable T cast(Class<T> type, @Nullable Object value) {

 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public class AbstractTester<G> extends TestCase {
  private G subjectGenerator;
  private String suiteName;
  private @Nullable Runnable setUp;
  private @Nullable Runnable tearDown;

  // public so that it can be referenced in generated GWT tests.
  @Override
  public void setUp() throws Exception {
    if (setUp != null) {
      setUp.run();
    }
  }