pkg: analysis aided cleanup

pkg/unittest/test/matchers_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.
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:unittest/unittest.dart';
 
-import 'test_common.dart';
 import 'test_utils.dart';
 
 void main() {
 
   initUtils();
 
   // Core matchers
 
   group('Core matchers', () {
 
@@ skipping 736 matching lines @@
 
   X() {
     print(foo);
   }
 }
 
 abstract class Abstraction {
   void norealization();
 }