Completion should not show overridden inherited methods

pkg/analysis_server/lib/src/services/completion/dart_completion_manager.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 services.completion.dart;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/arglist_computer.dart';
@@ skipping 299 matching lines @@
   /**
    * The length of the text to be replaced if the remainder of the identifier
    * containing the cursor is to be replaced when the suggestion is applied
    * (that is, the number of characters in the existing identifier).
    */
   int replacementLength;
 
   /**
    * The list of suggestions to be sent to the client.
    */
-  final List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
+  final List<CompletionSuggestion> _suggestions = <CompletionSuggestion>[];
+
+  /**
+   * The set of completions used to prevent duplicates
+   */
+  final Set<String> _completions = new Set<String>();
 
   DartCompletionRequest(this.context, this.searchEngine, this.source,
       int offset, this.cache, CompletionPerformance performance)
       : super(offset, performance);
 
   /**
    * Return the original text from the [replacementOffset] to the [offset]
    * that can be used to filter the suggestions on the server side.
    */
   String get filterText {
     return context.getContents(source).data.substring(
         replacementOffset, offset);
   }
 
   /**
    * Information about the types of suggestions that should be included.
    * The [target] must be set first.
    */
   OpType get optype {
     if (_optype == null) {
       _optype = new OpType.forCompletion(target, offset);
     }
     return _optype;
   }
 
   /**
+   * The list of suggestions to be sent to the client.
+   */
+  Iterable<CompletionSuggestion> get suggestions => _suggestions;
+
+  /**
+   * Add the given suggestion to the list that is returned to the client as long
+   * as a suggestion with an identical completion has not already been added.
+   */
+  void addSuggestion(CompletionSuggestion suggestion) {
+    if (_completions.add(suggestion.completion)) {
+      _suggestions.add(suggestion);
+    }
+  }
+
+  /**
    * Convert all [CompletionSuggestionKind.INVOCATION] suggestions
    * to [CompletionSuggestionKind.IDENTIFIER] suggestions.
    */
   void convertInvocationsToIdentifiers() {
-    for (int index = suggestions.length - 1; index >= 0; --index) {
-      CompletionSuggestion suggestion = suggestions[index];
+    for (int index = _suggestions.length - 1; index >= 0; --index) {
+      CompletionSuggestion suggestion = _suggestions[index];
       if (suggestion.kind == CompletionSuggestionKind.INVOCATION) {
         // Create a copy rather than just modifying the existing suggestion
         // because [DartCompletionCache] may be caching that suggestion
         // for future completion requests
-        suggestions[index] = new CompletionSuggestion(
+        _suggestions[index] = new CompletionSuggestion(
             CompletionSuggestionKind.IDENTIFIER, suggestion.relevance,
             suggestion.completion, suggestion.selectionOffset,
             suggestion.selectionLength, suggestion.isDeprecated,
             suggestion.isPotential,
             declaringType: suggestion.declaringType,
             parameterNames: suggestion.parameterNames,
             parameterTypes: suggestion.parameterTypes,
             requiredParameterCount: suggestion.requiredParameterCount,
             hasNamedParameters: suggestion.hasNamedParameters,
             returnType: suggestion.returnType,
             element: suggestion.element);
       }
     }
   }
 }