DOCBOOK: class extends superclass

[Elliotte Rusty Harold <elharo@metalab.unc.edu>]

In a DocBook 4.1.2 classynopsis how should one indicate the superclass 
which a class or interface extends? e.g. I have

    <classsynopsis language="Java">
      <ooclass>
        <classname>SAXParserFactory</classname>
        <modifier>public</modifier>
        <modifier>abstract</modifier>
      </ooclass>
</classsynopsis>

I need:

    <classsynopsis language="Java">
      <ooclass>
        <classname>SAXParserFactory</classname>
        <modifier>public</modifier>
        <modifier>abstract</modifier>
       <extends>Object</extends>
      </ooclass>
</classsynopsis>


Is there an element I'm missing somewhere? or would the following work:

    <classsynopsis language="Java">
      <ooclass>
        <modifier>public</modifier>
        <modifier>abstract</modifier>
        <classname>SAXParserFactory</classname>
       <modifier>extends Object</modifier>
      </ooclass>
</classsynopsis>

It's not really a modifier though.

-- 
+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+ 
|           The XML Bible, 2nd Edition (IDG Books, 2001)             |
|             http://www.cafeconleche.org/books/bible2/              |
|   http://www.amazon.com/exec/obidos/ISBN=0764547607/cafeaulaitA/   |
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