anchor.diff:  import 'dart:async';
   
   import 'package:analysis_server/src/protocol.dart';
  +import 'package:unittest/unittest.dart';
  +
   import '../reflective_tests.dart';
  -import 'package:unittest/unittest.dart';
  -
   import 'abstract_search_domain.dart';
   
   
  
positive.code:     });
    }
  
    test_topLevelVariable_explicit() {
      addTestFile('''
  var vvv = 1;
  
negative.code: @ReflectiveTestCase()
  class ElementReferencesTest extends AbstractSearchDomainTest {
    Element searchElement;
  
    void assertHasRef(SearchResultKind kind, String search, bool isPotential) {
      assertHasResult(kind, search);
      expect(result.isPotential, isPotential);
    }
  
    Future findElementReferences(String search, bool includePotential) {
      int offset = findOffset(search);
  