() -> Suppliers.memoizeWithExpiration(() -> "", 0, MILLISECONDS));

    assertThrows(
        IllegalArgumentException.class,
        () -> Suppliers.memoizeWithExpiration(() -> "", -1, MILLISECONDS));
  }

  @J2ktIncompatible // Duration
  @GwtIncompatible // Duration
  public void testMemoizeWithExpiration_durationNegative() throws InterruptedException {
    assertThrows(

   * @throws IllegalArgumentException if {@code duration} is not positive
   * @since 2.0
   */
  @SuppressWarnings("GoodTime") // Prefer the Duration overload
  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(
      Supplier<T> delegate, long duration, TimeUnit unit) {
    checkNotNull(delegate);
    checkArgument(duration > 0, "duration (%s %s) must be > 0", duration, unit);

   * @throws IllegalArgumentException if {@code duration} is not positive
   * @since 2.0
   */
  @SuppressWarnings("GoodTime") // Prefer the Duration overload
  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(
      Supplier<T> delegate, long duration, TimeUnit unit) {
    checkNotNull(delegate);
    checkArgument(duration > 0, "duration (%s %s) must be > 0", duration, unit);