Index: sdk/lib/json/json.dart |
diff --git a/sdk/lib/json/json.dart b/sdk/lib/json/json.dart |
index e30dc57cfd479d4afb2f0682de530abe121d718f..31d14eef8d51b3f54d2979b5428d5f178a07819b 100644 |
--- a/sdk/lib/json/json.dart |
+++ b/sdk/lib/json/json.dart |
@@ -16,7 +16,7 @@ library dart.json; |
* [cause] field. If the call returns an object that isn't directly |
* serializable, the [cause] will be null. |
*/ |
-class JsonUnsupportedObjectError implements Error { |
+class JsonUnsupportedObjectError extends Error { |
/** The object that could not be serialized. */ |
final unsupportedObject; |
/** The exception thrown by object's [:toJson:] method, if any. */ |