@Override
    public void save(@NotNull DataOutput out, TimestampPerTarget[] value) throws IOException {
      out.writeInt(value.length);
      for (TimestampPerTarget target : value) {
        out.writeInt(target.targetId);
        out.writeLong(target.timestamp);
      }
    }
@Override
    public void save(@NotNull DataOutput out, TimestampPerTarget[] value)