extract LabelContributor from local reference contributor

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/plugin/protocol/protocol.dart' as protocol
     show Element, ElementKind;
@@ skipping 287 matching lines @@
     expect(element, isNotNull);
     expect(element.kind, equals(protocol.ElementKind.GETTER));
     expect(element.name, equals(name));
     expect(element.parameters, isNull);
     expect(element.returnType,
         equals(returnType != null ? returnType : 'dynamic'));
     assertHasNoParameterInfo(cs);
     return cs;
   }
 
-  CompletionSuggestion assertSuggestLabel(String name,
-      [int relevance = DART_RELEVANCE_DEFAULT,
-      CompletionSuggestionKind kind = CompletionSuggestionKind.IDENTIFIER]) {
-    CompletionSuggestion cs =
-        assertSuggest(name, csKind: kind, relevance: relevance);
-    expect(cs.returnType, isNull);
-    protocol.Element element = cs.element;
-    expect(element, isNotNull);
-    expect(element.flags, 0);
-    expect(element.kind, equals(protocol.ElementKind.LABEL));
-    expect(element.name, equals(name));
-    expect(element.parameters, isNull);
-    expect(element.returnType, isNull);
-    assertHasNoParameterInfo(cs);
-    return cs;
-  }
-
   CompletionSuggestion assertSuggestLibraryPrefix(String prefix,
       [int relevance = DART_RELEVANCE_DEFAULT,
       CompletionSuggestionKind kind = CompletionSuggestionKind.INVOCATION]) {
     // Library prefix should only be suggested by ImportedReferenceContributor
     return assertNotSuggested(prefix);
   }
 
   CompletionSuggestion assertSuggestMethod(
       String name, String declaringType, String returnType,
       {int relevance: DART_RELEVANCE_DEFAULT,
@@ skipping 4351 matching lines @@
       assertNotSuggested('bar2');
       assertNotSuggested('_B');
       assertSuggestLocalClass('Y');
       assertSuggestLocalClass('C');
       assertSuggestLocalVariable('f', null);
       assertNotSuggested('x');
       assertNotSuggested('e');
     });
   }
 }