TrustedListenableFutureTask<@Nullable Void> task =
          TrustedListenableFutureTask.create(command, null);
      ScheduledFuture<?> scheduled = delegate.schedule(task, delay, unit);
      return new ListenableScheduledTask<@Nullable Void>(task, scheduled);
    }

    @Override
    public <V extends @Nullable Object> ListenableScheduledFuture<V> schedule(

interface IThenable<T extends @Nullable Object> {
  <V extends @Nullable Object> IThenable<V> then(
      @JsOptional @Nullable IThenOnFulfilledCallbackFn<? super T, ? extends V> onFulfilled,
      @JsOptional @Nullable IThenOnRejectedCallbackFn<? extends V> onRejected);

  @JsFunction
  interface IThenOnFulfilledCallbackFn<T extends @Nullable Object, V extends @Nullable Object> {
    V onInvoke(T p0);
  }

            return Lists.transform(objs, OPTIONAL_TO_NULLABLE);
          }
        });
  }

  private CacheBuilder<Object, Object> createCacheBuilder(
      @Nullable Integer concurrencyLevel,
      @Nullable Integer initialCapacity,
      @Nullable Integer maximumSize,
      @Nullable DurationSpec expireAfterWrite,
      @Nullable DurationSpec expireAfterAccess,
      @Nullable DurationSpec refresh,

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

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class Helpers {
  // Clone of Objects.equal
  static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {

  @Generates
  static <K, V> Map<K, V> generateMap(@Nullable K key, @Nullable V value) {
    return generateHashdMap(key, value);
  }

  @Generates
  static <K, V> HashMap<K, V> generateHashdMap(@Nullable K key, @Nullable V value) {
    return generateLinkedHashMap(key, value);
  }

  @Generates
  static <K, V> LinkedHashMap<K, V> generateLinkedHashMap(@Nullable K key, @Nullable V value) {

   */
  public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {
    return new FunctionComposition<>(g, f);
  }

  private static class FunctionComposition<
          A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      implements Function<A, C>, Serializable {

   */
  static <T extends @Nullable Object> T[] toArrayImpl(
      @Nullable Object[] src, int offset, int len, T[] dst) {
    checkPositionIndexes(offset, offset + len, src.length);
    if (dst.length < len) {
      dst = newArray(dst, len);
    } else if (dst.length > len) {
      @Nullable Object[] unsoundlyCovariantArray = dst;
      unsoundlyCovariantArray[len] = null;
    }

                return (from == null) ? true : null;
              }
            });

    Set<Entry<@Nullable String, @Nullable Boolean>> entries = map.entrySet();
    assertTrue(entries.contains(Maps.immutableEntry("a", true)));
    assertTrue(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("b", null)));
    assertTrue(

    public @Nullable K floorKey(K key) {
      return standardFloorKey(key);
    }

    @Override
    public @Nullable Entry<K, V> ceilingEntry(K key) {
      return standardCeilingEntry(key);
    }

    @Override
    public @Nullable K ceilingKey(K key) {
      return standardCeilingKey(key);
    }

    @Override
    public @Nullable Entry<K, V> higherEntry(K key) {
      return standardHigherEntry(key);

    public static Object good(
        String a,
        int b,
        // oneConstantOnly doesn't matter since it's not nullable and can be only 1 value.
        @SuppressWarnings("unused") OneConstantEnum oneConstantOnly,
        // noConstant doesn't matter since it can only be null
        @SuppressWarnings("unused") @Nullable NoConstantEnum noConstant) {
      return new GoodEquals(a, b);
    }

    // instance method ignored