Wrapping leaf nodes in non polymer elements

runtime/observatory/lib/src/mocks/repositories/dump.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file
+
+part of mocks;
+
+typedef void DumpRepositoryMockCallback(Map);
+
+class DumpRepositoryMock implements M.DumpRepository {
+  final DumpRepositoryMockCallback wrapped;
+
+  void load(Map dump) => wrapped(dump);
+
+  DumpRepositoryMock(this.wrapped);
+}