@Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return trustedGet(TypeToken.of(type));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(TypeToken<T> type) {
    return trustedGet(type.rejectTypeVariables());
  }

  @Override
  @CanIgnoreReturnValue
  public <T extends B> @Nullable T putInstance(

import java.util.concurrent.ExecutionException;
import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link AbstractLoadingCache}.
 *
 * @author Charles Fry
 */
@NullUnmarked
public class AbstractLoadingCacheTest extends TestCase {

  public void testGetUnchecked_checked() {

    Multiset<N> successors = getReference(successorsReference);
    if (successors != null) {
      checkState(successors.add(node));
    }
  }

  private static <T> @Nullable T getReference(@Nullable Reference<T> reference) {
    return (reference == null) ? null : reference.get();
  }

    Multiset<N> successors = getReference(successorsReference);
    if (successors != null) {
      checkState(successors.add(node));
    }
  }

  private static <T> @Nullable T getReference(@Nullable Reference<T> reference) {
    return (reference == null) ? null : reference.get();
  }

  }

  public void testCopyOf_nullArray() {
    assertThrows(NullPointerException.class, () -> copyOf((String[]) null));
  }

  public void testCopyOf_arrayContainingOnlyNull() {
    @Nullable String[] array = new @Nullable String[] {null};
    assertThrows(NullPointerException.class, () -> copyOf((String[]) array));
  }

  public void testCopyOf_collection_empty() {
    Collection<String> c = MinimalCollection.of();

    public CustomScheduler() {}

    /** A callable class that can reschedule itself using a {@link CustomScheduler}. */
    private final class ReschedulableCallable implements Callable<@Nullable Void> {

      /** The underlying task. */
      private final Runnable wrappedRunnable;

      /** The executor on which this Callable will be scheduled. */
      private final ScheduledExecutorService executor;

            MultimapBuilder.linkedHashKeys().linkedHashSetValues()::<K, V>build),
        ImmutableSetMultimap::copyOf);
  }

  static <
          T extends @Nullable Object,
          K extends @Nullable Object,
          V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> toMultimap(
          Function<? super T, ? extends K> keyFunction,

            MultimapBuilder.linkedHashKeys().linkedHashSetValues()::<K, V>build),
        ImmutableSetMultimap::copyOf);
  }

  static <
          T extends @Nullable Object,
          K extends @Nullable Object,
          V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> toMultimap(
          Function<? super T, ? extends K> keyFunction,

    return super.toString();
  }

  @Override
  public boolean equals(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.equals(o);
  }

  @Override
  public int hashCode() {
    assertTrue(Thread.holdsLock(mutex));
    return super.hashCode();
  }

  @Override
  public boolean add(@Nullable E o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.add(o);
  }

import java.util.Collection;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Generator for collection of a particular size.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public final class OneSizeGenerator<T, E extends @Nullable Object>
    implements OneSizeTestContainerGenerator<T, E> {
  private final TestContainerGenerator<T, E> generator;