code: public void pushStylesheet(Stylesheet s)
    {
  
      if (m_stylesheets.size() == 0)
        m_stylesheetRoot = (StylesheetRoot) s;
  
      m_stylesheets.push(s);
    }
docs: Push the current stylesheet being constructed. If no other stylesheets
  have been pushed onto the stack, assume the argument is a stylesheet
  root, and also set the stylesheet root member.
  
  @param s non-null reference to a stylesheet.