refactor duplicate code into single visitor

pkg/analysis_server/test/services/completion/completion_test_util.dart

 // Copyright (c) 2014, 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.
 
 library test.services.completion.util;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart' as protocol show Element,
     ElementKind;
@@ skipping 1378 matching lines @@
       CompletionSuggestion suggestionB = assertSuggestLocalClass('_B');
       if (suggestionB != null) {
         expect(suggestionB.element.isDeprecated, isFalse);
         expect(suggestionB.element.isPrivate, isTrue);
       }
       CompletionSuggestion suggestionO = assertSuggestImportedClass('Object');
       if (suggestionO != null) {
         expect(suggestionO.element.isDeprecated, isFalse);
         expect(suggestionO.element.isPrivate, isFalse);
       }
-      assertSuggestLocalTopLevelVar('T', 'A');
+      assertNotSuggested('T');
       assertSuggestLibraryPrefix('x');
     });
   }
 
   test_Combinator_hide() {
     // SimpleIdentifier  HideCombinator  ImportDirective
     addSource('/testAB.dart', '''
       library libAB;
       part '/partAB.dart';
       class A { }
@@ skipping 1001 matching lines @@
       assertNotSuggested('bar2');
       assertNotSuggested('_B');
       assertSuggestLocalClass('Y');
       assertSuggestLocalClass('C');
       assertSuggestLocalVariable('f', null);
       assertNotSuggested('x');
       assertNotSuggested('e');
     });
   }
 }