code: public final Cache2kBuilder<K, V> expireAfterWrite(long v, TimeUnit u) {
      config().setExpireAfterWrite(u.toMillis(v));
      return this;
    }
docs: Time duration after insert or updated an cache entry expires.
  To switch off time based expiry use {@link #eternal(boolean)}.
  
  <p>If an {@link ExpiryPolicy} is specified, the maximum expiry duration
  is capped to the value specified here.
  
  <p>A value of {@code 0} means every entry should expire immediately. Low values or
  {@code 0} together with read through operation mode with a {@link CacheLoader} should be
  avoided in production environments.
  
  @throws IllegalArgumentException if {@link #eternal(boolean)} was set to true
  @see <a href="https://cache2k.org/docs/latest/user-guide.html#expiry-and-refresh">cache2k user guide - Expiry and Refresh</a>