First step for fixing Issue 9416.

tests/isolate/spawn_uri_nested_vm_test.dart

+// Copyright (c) 2012, 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.
+
+// Example of nested spawning of isolates from a URI
+// Note: the following comment is used by test.dart to additionally compile the
+// other isolate's code.
+// OtherScripts=spawn_uri_nested_child1_vm_isolate.dart, spawn_uri_nested_child2_vm_isolate.dart
+library NestedSpawnUriLibrary;
+import 'dart:isolate';
+import '../../pkg/unittest/lib/unittest.dart';
+
+main() {
+  test('isolate fromUri - nested send and reply', () {
+    var port = spawnUri('spawn_uri_nested_child1_vm_isolate.dart');
+  
+    port.call([1, 2]).then((result) => print(result));
+  });
+}