CacheBuilder.newBuilder().refreshAfterWrite(Duration.ofHours(1));
    assertThrows(IllegalStateException.class, () -> builder.refreshAfterWrite(Duration.ofHours(1)));
  }

  public void testTicker_setTwice() {
    Ticker testTicker = Ticker.systemTicker();
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().ticker(testTicker);
    assertThrows(IllegalStateException.class, () -> builder.ticker(testTicker));