code: public void defaultReadObject ()
          throws IOException, ClassNotFoundException
      {
          // sanity check
          if (_current == null) {
              throw new RuntimeException("defaultReadObject() called illegally.");
          }
  
          // read the instance data
          _streamer.readObject(_current, this, false);
      }
docs: Reads the fields of the specified {@link Streamable} instance from the input stream using
  the default object streaming mechanisms (a call is not made to <code>readObject()</code>,
  even if such a method exists).