code: public void compose(StylesheetRoot sroot) 
      throws javax.xml.transform.TransformerException
    {
      super.compose(sroot);
      java.util.Vector vnames = sroot.getComposeState().getVariableNames();
      if(null != m_matchPattern)
        m_matchPattern.fixupVariables(vnames, sroot.getComposeState().getGlobalsSize());
      if(null != m_use)
        m_use.fixupVariables(vnames, sroot.getComposeState().getGlobalsSize());
    }
docs: This function is called after everything else has been
  recomposed, and allows the template to set remaining
  values that may be based on some other property that
  depends on recomposition.