import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * {@code keySet()} implementation for {@link ImmutableMap}.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible

import com.google.common.annotations.GwtCompatible;
import java.util.Queue;
import org.jspecify.annotations.Nullable;

/**
 * An Iterator implementation which draws elements from a queue, removing them from the queue as it
 * iterates. This class is not thread safe.
 */
@GwtCompatible
final class ConsumingQueueIterator<T extends @Nullable Object> extends AbstractIterator<T> {
  private final Queue<T> queue;

import com.google.common.annotations.J2ktIncompatible;
import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *

  // But before Java 9, our only way not to inherit ThreadLocals is to zap them after the thread
  // is created, by accessing a private field.
  private static final @Nullable Constructor<Thread> bigThreadConstructor =
      getBigThreadConstructor();

  private static final @Nullable Field inheritableThreadLocals =
      (bigThreadConstructor == null) ? getInheritableThreadLocalsField() : null;

  /** Constructs a new finalizer thread. */

    return instance;
  }

  private static <T> @Nullable T invoke(Invokable<?, ? extends T> factory, List<?> args)
      throws InvocationTargetException, IllegalAccessException {
    T returnValue = factory.invoke(null, args.toArray());
    if (returnValue == null) {
      Assert.assertTrue(
          factory + " returns null but it's not annotated with @Nullable", isNullable(factory));
    }
    return returnValue;
  }

    checkNotNull(service);
    checkNotNull(nameSupplier);
    return new WrappingExecutorService(service) {
      @Override
      protected <T extends @Nullable Object> Callable<T> wrapTask(Callable<T> callable) {
        return threadRenaming(callable, nameSupplier);
      }

      @Override
      protected Runnable wrapTask(Runnable command) {
        return threadRenaming(command, nameSupplier);
      }

  }

  private ImmutableRangeSet(
      ImmutableList<Range<C>> ranges, @Nullable ImmutableRangeSet<C> complement) {
    this.ranges = ranges;
    this.complement = complement;
  }

  private final transient ImmutableList<Range<C>> ranges;
  private final transient @Nullable ImmutableRangeSet<C> complement;

  @Override
  public boolean intersects(Range<C> otherRange) {

Prefer either:
  * Provide only non-nullable version and move the `null` check to the call site (if the number of nullable callsites is low).
  * Provide two overloads with a different names (as Java doesn't support overloading on nullability). See 

  @Override
  ContiguousSet<C> tailSetImpl(C fromElement, boolean fromInclusive) {
    return this;
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return false;
  }

  @GwtIncompatible // not used by GWT emulation
  @Override
  int indexOf(@Nullable Object target) {
    return -1;
  }

  @Override
  public UnmodifiableIterator<C> iterator() {
    return emptyIterator();
  }

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractContainerTester<Map<K, V>, Entry<K, V>> {
  protected Map<K, V> getMap() {
    return container;
  }

  @Override
  protected Collection<Entry<K, V>> actualContents() {