remove duplicate completion suggestions

pkg/analysis_server/test/domain_completion_test.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.domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/channel/channel.dart';
@@ skipping 403 matching lines @@
     addTestFile('class A {A.c(); x() {new A.^}}');
     return getSuggestions().then((_) {
       expect(replacementOffset, equals(completionOffset));
       expect(replacementLength, equals(0));
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'c');
       assertNoResult('A');
     });
   }
 
   test_locals() {
-    addTestFile('class A {var a; x() {var b;^}}');
+    addTestFile('class A {var a; x() {var b;^}} class DateTime { }');
     return getSuggestions().then((_) {
       expect(replacementOffset, equals(completionOffset));
       expect(replacementLength, equals(0));
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'A');
       assertHasResult(
           CompletionSuggestionKind.INVOCATION, 'a', DART_RELEVANCE_LOCAL_FIELD);
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'b',
           DART_RELEVANCE_LOCAL_VARIABLE);
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'x',
           DART_RELEVANCE_LOCAL_METHOD);
+      assertHasResult(CompletionSuggestionKind.INVOCATION, 'DateTime');
     });
   }
 
   test_partFile() {
     addFile('/project/bin/testA.dart', '''
       library libA;
       part "$testFile";
       import 'dart:html';
       class A { }
     ''');
@@ skipping 229 matching lines @@
 }
     ''');
     await waitForTasksFinished();
     Request request =
         new CompletionGetSuggestionsParams(testFile, 0).toRequest('0');
     Response response = handler.handleRequest(request);
     expect(response.error, isNotNull);
     expect(response.error.code, RequestErrorCode.NO_INDEX_GENERATED);
   }
 }