// 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());

    /** Gets the weak value reference held by entry. */
    WeakValueReference<K, V, E> getValueReference();
  }

  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <K, V, E extends InternalEntry<K, V, E>>
      WeakValueReference<K, V, E> unsetWeakValueReference() {

   *       exceptions).
   * </ul>
   *
   * <p>The overall principle is to continue to treat every checked exception as a checked
   * exception, every unchecked exception as an unchecked exception, and every error as an error. In
   * addition, the cause of any {@code ExecutionException} is wrapped in order to ensure that the

    return new TreeRangeMap<>();
  }

  /**
   * Returns a new {@link TreeRangeMap} containing the same ranges as the given {@code RangeMap}.
   *
   * @since 33.4.0
   */
  @SuppressWarnings("unchecked")
  public static <K extends Comparable<?>, V> TreeRangeMap<K, V> copyOf(
      RangeMap<K, ? extends V> rangeMap) {
    if (rangeMap instanceof TreeRangeMap) {

            final Object readingObj = source.get(FieldNames.READING_PREFIX + i);
            if (!(readingObj instanceof List)) {
                break;
            }
            @SuppressWarnings("unchecked")
            final List<String> list = (List<String>) readingObj;
            readings.add(list.toArray(new String[list.size()]));
        }

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

   * @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();

    return backingMap;
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T
  private <T extends B> @Nullable T trustedPut(
      TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return (T) backingMap.put(type, value);
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T

   * @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();

  // but types are typically only Comparable to themselves).
  @SuppressWarnings({"rawtypes", "unchecked"})
  private static MultimapBuilderWithKeys<Comparable<?>> rawtypeToWildcard(
      MultimapBuilderWithKeys<Comparable> treeKeys) {
    return (MultimapBuilderWithKeys) treeKeys;
  }

  @SuppressWarnings({"rawtypes", "unchecked"})
  private static <K extends @Nullable Object>