return emptyListIterator();
  }

  /**
   * Returns the empty iterator.
   *
   * <p>The {@link Iterable} equivalent of this method is {@link ImmutableSet#of()}.
   */
  // Casting to any type is safe since there are no actual elements.
  @SuppressWarnings("unchecked")
  static <T extends @Nullable Object> UnmodifiableListIterator<T> emptyListIterator() {
    return (UnmodifiableListIterator<T>) ArrayItr.EMPTY;

    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  /**
   * Returns the empty bimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {
    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

  @Override
  public abstract int hashCode();

  /*
   * The implementation neither produces nor consumes any non-null instance of type C, so
   * casting the type parameter is safe.
   */
  @SuppressWarnings("unchecked")
  static <C extends Comparable> Cut<C> belowAll() {
    return (Cut<C>) BelowAll.INSTANCE;
  }

          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {
    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

  private static FluentIterable<? extends Number> getSomeNumbers() {
    return FluentIterable.from(ImmutableList.<Number>of());
  }

  /*
   * The following tests demonstrate the shortcomings of or() and test that the casting workaround
   * mentioned in the method Javadoc does in fact compile.
   */

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError1() {

    }
    return Collections.unmodifiableList(causes);
  }

  /**
   * Returns {@code throwable}'s cause, cast to {@code expectedCauseType}.
   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code

    }
    return Collections.unmodifiableList(causes);
  }

  /**
   * Returns {@code throwable}'s cause, cast to {@code expectedCauseType}.
   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code

     *          since casting to double is nondecreasing.
     *          Note that the right-hand inequality is no longer strict.
     * Math.sqrt(k * k) <= Math.sqrt(x) <= Math.sqrt((k + 1) * (k + 1))
     *          since Math.sqrt is monotonic.
     * (long) Math.sqrt(k * k) <= (long) Math.sqrt(x) <= (long) Math.sqrt((k + 1) * (k + 1))
     *          since casting to long is monotonic

   */
  private static int getAlphaIndex(char c) {
    // Fold upper-case ASCII to lower-case and make zero-indexed and unsigned (by casting to char).
    return (char) ((c | CASE_MASK) - 'a');
  }

  }

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSetMultimap<K, V> of() {
    return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;