code: public void setVariable(ElemVariable v)
    {
  
      if (null == m_topLevelVariables)
        m_topLevelVariables = new Vector();
  
      m_topLevelVariables.addElement(v);
    }
docs: Set the "xsl:variable" property.
  @see <a href="http://www.w3.org/TR/xslt#top-level-variables">top-level-variables in XSLT Specification</a>
  
  @param v ElemVariable object to add to list of top level variables