// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
  // +optional
  optional Time deletionTimestamp = 9;

  // Number of seconds allowed for this object to gracefully terminate before
  // it will be removed from the system. Only set when deletionTimestamp is also set.
  // May only be shortened.
  // Read-only.
  // +optional
  optional int64 deletionGracePeriodSeconds = 10;

      out.writeInt(delegate.size());
      for (Entry<K, V> entry : delegate.entrySet()) {
        out.writeObject(entry.getKey());
        out.writeObject(entry.getValue());
      }
      out.writeObject(null); // terminate entries
    }

    @SuppressWarnings("deprecation") // serialization of deprecated feature
    @J2ktIncompatible // java.io.ObjectInputStream
    MapMaker readMapMaker(ObjectInputStream in) throws IOException {

      out.writeInt(delegate.size());
      for (Entry<K, V> entry : delegate.entrySet()) {
        out.writeObject(entry.getKey());
        out.writeObject(entry.getValue());
      }
      out.writeObject(null); // terminate entries
    }

    @SuppressWarnings("deprecation") // serialization of deprecated feature
    @J2ktIncompatible // java.io.ObjectInputStream
    MapMaker readMapMaker(ObjectInputStream in) throws IOException {