anchor.diff:          isEmpty);
     }
   
  -  void expectSuggestion({
  +  void assertSuggestion({
  +    @required String completion,
  +    ElementKind element,
  +    CompletionSuggestionKind kind,
  +    String file,
  +  }) {
  +    expect(
  +        suggestionWith(
  +          completion: completion,
  +          element: element,
  +          kind: kind,
  +          file: file,
  +        ),
  +        isNotNull);
  +  }
  +
  +  void assertSuggestions({
       @required String completion,
       ElementKind element,
       CompletionSuggestionKind kind,
  
positive.code:     // A kind-filtered set of SDK suggestions.
  
      // Constructors should be visible.
      expectSuggestion(
          completion: 'Timer',
          file: '/sdk/lib/async/async.dart',
          element: ElementKind.CONSTRUCTOR,
          kind: CompletionSuggestionKind.INVOCATION);
  
      // But not methods.
      expectNoSuggestion(
          // dart:async (StreamSubscription)
          completion: 'asFuture',
          element: ElementKind.METHOD,
          kind: CompletionSuggestionKind.INVOCATION);
  
      // +  Functions.
      expectSuggestion(
          completion: 'print',
          file: '/sdk/lib/core/core.dart',
          element: ElementKind.FUNCTION,
          kind: CompletionSuggestionKind.INVOCATION);
      expectSuggestion(
          completion: 'tan',
          file: '/sdk/lib/math/math.dart',
          element: ElementKind.FUNCTION,
          kind: CompletionSuggestionKind.INVOCATION);
  
      // + Classes.
      expectSuggestion(
          completion: 'HashMap',
          file: '/sdk/lib/collection/collection.dart',
          element: ElementKind.CLASS,
          kind: CompletionSuggestionKind.INVOCATION);
  
      // + Top level variables.
      expectSuggestion(
          completion: 'PI',
          file: '/sdk/lib/math/math.dart',
          element: ElementKind.TOP_LEVEL_VARIABLE,
  
negative.code: }
  ''');
  
      assertSuggestion(
          completion: 'A.a',
          element: ElementKind.CONSTRUCTOR,
          kind: CompletionSuggestionKind.INVOCATION);
  