private Set totalValueSet() {
   Set values = new HashSet();
   List<Integer> scopes = context.getScopes();
   for (int i : scopes) {
     values.addAll(context.getBindings(i).values());
   }
   return Collections.unmodifiableSet(values);
 }
 private Set totalKeySet() {
   Set keys = new HashSet();
   List<Integer> scopes = context.getScopes();
   for (int i : scopes) {
     keys.addAll(context.getBindings(i).keySet());
   }
   return Collections.unmodifiableSet(keys);
 }