         {
             newSet = new Set();
             for each (item in a.dict)
+            {
                 if (b.contains(item))
+                {
                     newSet.add(item);
+                }
+            }
         }
 
         return newSet;

        {
            newSet = a.clone();
            for each (item in b.dict)
                if (!newSet.remove(item))
                    newSet.add(item);
        }

        return newSet;

        var newSet:Set = a.clone();

        if (a !== b)
        {
            newSet.addIterable(b.dict);
        }

        return newSet;
    }
