@Beta // only until we're confident that Java 8+ APIs are safe for our Android users
  @J2ktIncompatible
  @GwtIncompatible // java.time.Duration
  @SuppressWarnings("Java7ApiChecker") // no more dangerous that wherever the user got the Duration
  @IgnoreJRERequirement
  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(
      Supplier<T> delegate, Duration duration) {
    checkNotNull(delegate);

   *     RuntimeException(e)}. But consider whether users would be better off if your API threw a
   *     different type of exception. For background on the deprecation, read <a
   *     href="https://goo.gl/Ivn2kc">Why we deprecated {@code Throwables.propagate}</a>.
   */
  @CanIgnoreReturnValue
  @J2ktIncompatible
  @GwtIncompatible
  @Deprecated
  public static RuntimeException propagate(Throwable throwable) {

   *     RuntimeException(e)}. But consider whether users would be better off if your API threw a
   *     different type of exception. For background on the deprecation, read <a
   *     href="https://goo.gl/Ivn2kc">Why we deprecated {@code Throwables.propagate}</a>.
   */
  @CanIgnoreReturnValue
  @J2ktIncompatible
  @GwtIncompatible
  @Deprecated
  public static RuntimeException propagate(Throwable throwable) {

/**
 * Static methods to obtain {@link HashFunction} instances, and other static hashing-related
 * utilities.
 *
 * <p>A comparison of the various hash functions can be found <a
 * href="http://goo.gl/jS7HH">here</a>.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 * @author Kurt Alfred Kluever
 * @since 11.0
 */
@ElementTypesAreNonnullByDefault
public final class Hashing {
  /**

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code ArrayList} {@linkplain ArrayList#ArrayList() constructor} directly, taking
   * advantage of <a href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   */
  @GwtCompatible(serializable = true)
  public static <E extends @Nullable Object> ArrayList<E> newArrayList() {
    return new ArrayList<>();
  }

  /**

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashSet} constructor directly, taking advantage of <a
   * href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   */
  public static <E extends @Nullable Object> HashSet<E> newHashSet() {
    return new HashSet<>();
  }

  /**

    // plus the exception mechanics account for messiness of main
    // loop.

    try {
      // Record exceptions so that if we fail to obtain any
      // result, we can throw the last exception we got.
      ExecutionException ee = null;
      long lastTime = timed ? System.nanoTime() : 0;
      Iterator<? extends Callable<T>> it = tasks.iterator();

  interface WeakValueReference<K, V, E extends InternalEntry<K, V, E>> {
    /**
     * Returns the current value being referenced, or {@code null} if there is none (e.g. because
     * either it got collected, or {@link #clear} was called, or it wasn't set in the first place).
     */
    @CheckForNull
    V get();

    /** Returns the entry which contains this {@link WeakValueReference}. */
    E getEntry();

        assertTrue(expectedSuccess);
      } catch (ArithmeticException e) {
        if (expectedSuccess) {
          failFormat("expected log10(%s, UNNECESSARY) = %s; got ArithmeticException", x, floor);
        }
      }
    }
  }

  @GwtIncompatible // TODO
  public void testLog10TrivialOnPowerOf10() {
    long x = 1000000000000L;

   */
  private void checkIsE(Object element) {
    checkNotNull(element);
    if (!isActuallyE(element)) {
      throw new ClassCastException("Expected an " + type + " but got " + element);
    }
  }

  @Override
  int distinctElements() {
    return distinctElements;
  }

  @Override
  public int size() {
    return Ints.saturatedCast(size);
  }