anchor.diff:  
     test_parts_invalidUri_nullStringValue() async {
       allowMissingFiles = true;
  -    shouldCompareLibraryElements = false;
       addSource('/foo/bar.dart', 'part of my.lib;');
       var library = await checkLibrary(r'''
   library my.lib;
  
positive.code:   }
  
    test_const_invokeConstructor_named_unresolved5() async {
      shouldCompareLibraryElements = false;
      var library = await checkLibrary(r'''
  const V = const p.C.named();
  ''', allowErrors: true);
  
negative.code:   }
  
    test_typedef_type_parameters_bound_recursive() async {
      var library = await checkLibrary('typedef void F<T extends F>();');
      // Typedefs cannot reference themselves.
      checkElementText(library, r'''
  