use Source.isInSystemLibrary

test/transformer_e2e_test.dart

Index: test/transformer_e2e_test.dart
diff --git a/test/transformer_e2e_test.dart b/test/transformer_e2e_test.dart
index 70beec8c8fdc740831135b04b9f8b5d55e3b1a06..a8f11d50b6c0a0bf636054441420ddd8a5c08ecb 100644
--- a/test/transformer_e2e_test.dart
+++ b/test/transformer_e2e_test.dart
@@ -69,7 +69,8 @@ main() {
 Future<ChildServerProcess> _startPubServe(String directory,
     [List<String> args = const []]) async {
   assert(new Directory(directory).existsSync());
-  var result = await Process.run('pub', ['upgrade'], workingDirectory: directory);
+  var result =
+      await Process.run('pub', ['upgrade'], workingDirectory: directory);
   if (result.exitCode != 0) {
     throw new StateError('Pub get failed: ${result.stderr}');
   }