pkg/test: cleanup imports

lib/src/runner/engine.dart

 // Copyright (c) 2015, 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.
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:async/async.dart' hide Result;
 import 'package:collection/collection.dart';
 import 'package:pool/pool.dart';
 
 import '../backend/group.dart';
+import '../backend/group_entry.dart';
 import '../backend/invoker.dart';
 import '../backend/live_test.dart';
 import '../backend/live_test_controller.dart';
 import '../backend/state.dart';
-import '../backend/group_entry.dart';
 import '../backend/test.dart';
 import 'load_suite.dart';
 import 'runner_suite.dart';
 
 /// An [Engine] manages a run that encompasses multiple test suites.
 ///
 /// Test suites are provided by passing them into [suiteSink]. Once all suites
 /// have been provided, the user should close [suiteSink] to indicate this.
 /// [run] won't terminate until [suiteSink] is closed. Suites will be run in the
 /// order they're provided to [suiteSink]. Tests within those suites will
@@ skipping 420 matching lines @@
     var futures = allLiveTests.map((liveTest) => liveTest.close()).toList();
 
     // Closing the load pool will close the test suites as soon as their tests
     // are done. For browser suites this is effectively immediate since their
     // tests shut down as soon as they're closed, but for VM suites we may need
     // to wait for tearDowns or tearDownAlls to run.
     futures.add(_loadPool.close());
     await Future.wait(futures, eagerError: true);
   }
 }