* @throws IllegalArgumentException if {@code duration} is negative
   * @throws IllegalStateException if {@link #refreshAfterWrite} was already set
   * @since 11.0
   */
  @GwtIncompatible // To be supported (synchronously).
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> refreshAfterWrite(long duration, TimeUnit unit) {
    checkNotNull(unit);

   * @throws IllegalArgumentException if {@code duration} is negative
   * @throws IllegalStateException if {@link #refreshAfterWrite} was already set
   * @since 11.0
   */
  @GwtIncompatible // To be supported (synchronously).
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> refreshAfterWrite(long duration, TimeUnit unit) {
    checkNotNull(unit);