} catch (UnsupportedOperationException e) {
      return;
    }

    map.put(null, unmappedValue);
    Entry<@Nullable K, V> entry = mapEntry(null, unmappedValue);
    assertTrue(entrySet.contains(entry));
    Entry<@Nullable K, @Nullable V> nonEntry = mapEntry(null, null);
    assertFalse(entrySet.contains(nonEntry));
  }

  public void testEntrySetContainsEntryNullKeyMissing() {

  private static final class NewExecutionListQueue {
    static final Logger log = Logger.getLogger(NewExecutionListQueue.class.getName());

    @GuardedBy("this")
    private @Nullable RunnableExecutorPair head;

    @GuardedBy("this")
    private @Nullable RunnableExecutorPair tail;

    @GuardedBy("this")
    private boolean executed;

    void add(Runnable runnable, Executor executor) {

   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */
  public void assertPriorCallReturns(boolean expected, @Nullable String methodName)
      throws Exception {

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;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Collections;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Encapsulates the constraints that a class under test must satisfy in order for a tester method to
 * be run against that class.
 *
 * @author George van den Driessche
 */
@GwtCompatible

import org.jspecify.annotations.Nullable;

/**
 * A callback for accepting the results of a {@link java.util.concurrent.Future} computation
 * asynchronously.
 *
 * <p>To attach to a {@link ListenableFuture} use {@link Futures#addCallback}.
 *
 * @author Anthony Zana
 * @since 10.0
 */
@GwtCompatible
public interface FutureCallback<V extends @Nullable Object> {

import com.google.common.annotations.GwtIncompatible;
import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * A {@link ScheduledExecutorService} that returns {@link ListenableFuture} instances from its
 * {@code ExecutorService} methods. To create an instance from an existing {@link
 * ScheduledExecutorService}, call {@link

  }

  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();

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * @author Luiz-Otavio "Z" Zorzella
 */
@GwtCompatible
@NullUnmarked
public class TearDownStackTest extends TestCase {

  private final TearDownStack tearDownStack = new TearDownStack();

import com.google.common.collect.testing.features.CollectionFeature;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Tester to make sure the {@code iterator().remove()} implementation of {@code Multiset} works when
 * there are multiple occurrences of elements.
 *
 * @author Louis Wasserman
 */