anchor.diff:  @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);
  
positive.code: import 'dart:async';
  
  import 'package:analysis_server/src/protocol.dart';
  import '../reflective_tests.dart';
  import 'package:unittest/unittest.dart';
  
  import 'abstract_search_domain.dart';
  
  
  
negative.code:     });
    }
  
    test_potential_method_definedInSubclass() {
      addTestFile('''
  class Base {
    methodInBase() {
      test(1);
    }
  }
  class Derived extends Base {
    test(_) {} // of Derived
    methodInDerived() {
      test(2);
    }
  }
  globalFunction(Base b) {
    b.test(3);
  }
  ''');
      return findElementReferences('test(_) {} // of Derived', true).then((_) {
        assertHasRef(SearchResultKind.INVOCATION, 'test(1);', true);
        assertHasRef(SearchResultKind.INVOCATION, 'test(2);', false);
        assertHasRef(SearchResultKind.INVOCATION, 'test(3);', true);
      });
    }
  
    test_topLevelVariable_explicit() {
      addTestFile('''
  var vvv = 1;
  