| Index: sdk/lib/core/set.dart | 
| diff --git a/sdk/lib/core/set.dart b/sdk/lib/core/set.dart | 
| index 1a8fd151cabed611e39cf48b6327ca95ad521372..ff8d4b3aac843b0619dcf97bb5c28ecc4bd11c6d 100644 | 
| --- a/sdk/lib/core/set.dart | 
| +++ b/sdk/lib/core/set.dart | 
| @@ -8,7 +8,7 @@ part of dart.core; | 
| * This class is the public interface of a set. A set is a collection | 
| * without duplicates. | 
| */ | 
| -abstract class Set<E> extends Iterable<E> { | 
| +abstract class Set<E> extends IterableBase<E> { | 
| factory Set() => new HashSet<E>(); | 
|  | 
| /** | 
|  |