WatchedCreatorLoader loader,
      FakeTicker ticker,
      String keyPrefix,
      long ttl) {
    loader.setKeyPrefix(keyPrefix);

    int shift1 = 10 + VALUE_PREFIX;
    loader.setValuePrefix(shift1);
    // fill with initial data
    for (int i = 0; i < 10; i++) {
      assertThat(cache.getUnchecked(keyPrefix + i)).isEqualTo(i + shift1);
    }