static boolean eq(XNode i_Left, XNode i_Right) {
   if (i_Left == null) {
     return (i_Right == null);
   } else {
     return (i_Right != null)
         && (i_Left.getStringValue().equals(i_Right.getStringValue())
             // FIXME: hack: blank nodes considered equal
             || (isBlank(i_Left) && isBlank(i_Right)));
   }
 }
 public static String toS(XNode n) {
   if (null == n) {
     return "< null >";
   }
   return n.getStringValue();
 }