code: String getRequiredElem()
    {
  		if (m_requiredFound == null)
  			return null;
  		Enumeration elems = m_requiredFound.elements();
  		String s = "";
  		boolean first = true;
  		while (elems.hasMoreElements())
  		{
  			if (first)
  				first = false;
  			else
  			 s = s + ", ";
  			s = s + (String)elems.nextElement();
  		}
      return s;
    }
docs: Get required elements that were not found.
  
  @return required elements that were not found.