assertTrue(Thread.holdsLock(mutex));
      return delegate.containsRow(rowKey);
    }

    @Override
    public @Nullable V get(Object rowKey, Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.get(rowKey, columnKey);
    }

    @Override
    public @Nullable V put(R rowKey, C columnKey, V value) {
      assertTrue(Thread.holdsLock(mutex));

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Derived suite generators, split out of the suite builders so that they are available to GWT.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class DerivedCollectionGenerators {
  public static class MapEntrySetGenerator<K extends @Nullable Object, V extends @Nullable Object>

})
abstract class AbstractTransformFuture<
        I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>
    extends FluentFuture.TrustedFuture<O> implements Runnable {
  static <I extends @Nullable Object, O extends @Nullable Object> ListenableFuture<O> createAsync(
      ListenableFuture<I> input,
      AsyncFunction<? super I, ? extends O> function,

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *

  @Override
  @ParametricNullness
  public <T extends @Nullable Object> T callWithTimeout(
      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit) throws ExecutionException {
    checkNotNull(callable);
    checkNotNull(timeoutUnit);
    try {
      return callable.call();
    } catch (RuntimeException e) {
      throw new UncheckedExecutionException(e);

import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.Nullable;

/**
 * An XML writer request.
 *
 * @since 4.0.0
 * @param <T> the object type to read
 */
@Experimental
public interface XmlWriterRequest<T> {

    @Nullable
    Path getPath();

    @Nullable
    OutputStream getOutputStream();

    @Nullable
    Writer getWriter();

    @Nonnull
    T getContent();

    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. */

    LAST_BEFORE {
      @Override
      public <E extends @Nullable Object> int resultIndex(
          Comparator<? super E> comparator,
          @ParametricNullness E key,
          List<? extends E> list,
          int foundIndex) {
        return FIRST_PRESENT.resultIndex(comparator, key, list, foundIndex) - 1;
      }
    };

    abstract <E extends @Nullable Object> int resultIndex(
        Comparator<? super E> comparator,

      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