docs: public CacheBuilder<K, V> expireAfterWrite(long duration, TimeUnit unit) {
      checkState(
          expireAfterWriteNanos == UNSET_INT,
          "expireAfterWrite was already set to %s ns",
          expireAfterWriteNanos);
      checkArgument(duration >= 0, "duration cannot be negative: %s %s", duration, unit);
      this.expireAfterWriteNanos = unit.toNanos(duration);
      return this;
    }