| Index: pkg/polymer/lib/src/instance.dart
|
| diff --git a/pkg/polymer/lib/src/instance.dart b/pkg/polymer/lib/src/instance.dart
|
| index f0bff99c4637274b00dd6c5d15419547f71b76d9..67f577b6a8ae966b4489886376cfa0a9d17d421e 100644
|
| --- a/pkg/polymer/lib/src/instance.dart
|
| +++ b/pkg/polymer/lib/src/instance.dart
|
| @@ -273,7 +273,7 @@ class PolymerElement extends CustomElement with ObservableMixin {
|
|
|
| void copyInstanceAttributes() {
|
| _declaration._instanceAttributes.forEach((name, value) {
|
| - attributes[name] = value;
|
| + attributes.putIfAbsent(name, () => value);
|
| });
|
| }
|
|
|
|
|