}

  public void testTimeToLive_setTwice() {
    CacheBuilder<Object, Object> builder =
        CacheBuilder.newBuilder().expireAfterWrite(3600, SECONDS);
    try {
      // even to the same value is not allowed
      builder.expireAfterWrite(3600, SECONDS);
      fail();
    } catch (IllegalStateException expected) {
    }
  }

  public void testTimeToIdle_negative() {

        CacheBuilder.newBuilder().refreshAfterWrite(3600, SECONDS);
    assertThrows(IllegalStateException.class, () -> builder.refreshAfterWrite(3600, SECONDS));
  }

  @GwtIncompatible // java.time.Duration
  public void testRefresh_setTwice_duration() {
    CacheBuilder<Object, Object> builder =
        CacheBuilder.newBuilder().refreshAfterWrite(java.time.Duration.ofSeconds(3600));
    assertThrows(