code: private void writeObject(java.io.ObjectOutputStream out) throws IOException
      {
          // Write non transient fields.
          out.defaultWriteObject();
  
          // Write transient fields.
          int n = ivPuIds.length;
          out.writeInt(n);
          for (int i = 0; i < n; ++i)
          {
              JPAPuId id = ivPuIds[i];
              out.writeObject(id);
          }
      }
docs: d468174