if (hasSameComparator && (elements instanceof ImmutableSortedSet)) {
      @SuppressWarnings("unchecked")
      ImmutableSortedSet<E> original = (ImmutableSortedSet<E>) elements;
      if (!original.isPartialView()) {
        return original;
      }
    }
    @SuppressWarnings("unchecked") // elements only contains E's; it's safe.
    E[] array = (E[]) Iterables.toArray(elements);

 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public final class SafeTreeSet<E> implements Serializable, NavigableSet<E> {
  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      (o1, o2) -> ((Comparable<Object>) o1).compareTo(o2);

  private final NavigableSet<E> delegate;

  public SafeTreeSet() {
    this(new TreeSet<E>());

 * @author George van den Driessche
 */
@GwtIncompatible
public abstract class FeatureSpecificTestSuiteBuilder<
    B extends FeatureSpecificTestSuiteBuilder<B, G>, G> {
  @SuppressWarnings("unchecked")
  protected B self() {
    return (B) this;
  }

  // Test Data

  private @Nullable G subjectGenerator;
  // Gets run before every test.
  private Runnable setUp;

   * - https://github.com/jspecify/jdk/commit/71d826792b8c7ef95d492c50a274deab938f2552
   */
  /*
   * TODO(cpovirk): Is the unchecked cast avoidable? Would System.arraycopy be similarly fast (if
   * likewise not type-checked)? Could our single caller do something different?
   */
  @SuppressWarnings({"nullness", "unchecked"})
  static <T extends @Nullable Object> T[] copy(Object[] source, int from, int to, T[] arrayOfType) {

    public @Nullable Collection<V> get(@Nullable Object key) {
      Collection<V> result = unfiltered.asMap().get(key);
      if (result == null) {
        return null;
      }
      @SuppressWarnings("unchecked") // key is equal to a K, if not a K itself
      K k = (K) key;
      result = filterCollection(result, new ValuePredicate(k));
      return result.isEmpty() ? null : result;
    }

    @Override

   *
   * @since 7.0
   */
  @Override
  protected boolean standardContains(@Nullable Object object) {
    try {
      // any ClassCastExceptions and NullPointerExceptions are caught
      @SuppressWarnings({"unchecked", "nullness"})
      SortedSet<@Nullable Object> self = (SortedSet<@Nullable Object>) this;
      Object ceiling = self.tailSet(object).first();
      return unsafeCompare(comparator(), ceiling, object) == 0;

    // We assume that all defaults are generics-safe, even if they aren't,
    // we take the risk.
    @SuppressWarnings("unchecked")
    T defaultValue = (T) defaults.getInstance(type.getRawType());
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // All arbitrary instances are generics-safe
    T arbitrary = (T) ArbitraryInstances.get(type.getRawType());

    // We assume that all defaults are generics-safe, even if they aren't,
    // we take the risk.
    @SuppressWarnings("unchecked")
    T defaultValue = (T) defaults.getInstance(type.getRawType());
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // All arbitrary instances are generics-safe
    T arbitrary = (T) ArbitraryInstances.get(type.getRawType());

        assertNotNull(response);
        assertEquals(0, response.getNumberOfInputDocs());
        assertFalse(response.hasError());
    }

    @Test
    @SuppressWarnings("unchecked")
    public void test_indexFromEmptyDocuments() throws Exception {
        Map<String, Object>[] documents = new Map[0];
        SuggestIndexResponse response = suggester.indexer().indexFromDocument(documents);

   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")
  public static <T> Collector<T, ?, Optional<T>> toOptional() {
    return (Collector) TO_OPTIONAL;
  }

  private static final Object NULL_PLACEHOLDER = new Object();