anchor.diff:      if (!_computeFastCalled) {
         expect(computeFast(), isFalse);
       }
  +
  +    // Index SDK
  +    for (Source librarySource in context.librarySources) {
  +      CompilationUnit unit = context.getResolvedCompilationUnit2(librarySource, librarySource);
  +      if (unit != null) {
  +          index.indexUnit(context, unit);
  +      }
  +    }
  +
       var result = context.performAnalysisTask();
       bool resolved = false;
       while (result.hasMoreWork) {
  
positive.code:     super.setUp();
      index = createLocalMemoryIndex();
      searchEngine = new SearchEngineImpl(index);
      addResolvedUnit(MockSdk.LIB_CORE.path, MockSdk.LIB_CORE.content);
    }
  }
  
negative.code: import 'dart:async';
  
  import 'package:analysis_server/src/protocol.dart';
  import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
  import 'package:analysis_server/src/services/index/index.dart';
  import 'package:analysis_server/src/services/index/local_memory_index.dart';
  import 'package:analysis_server/src/services/search/search_engine_internal.dart';
  import 'package:analyzer/src/generated/ast.dart';
  import 'package:analyzer/src/generated/element.dart';
  import 'package:analyzer/src/generated/engine.dart';
  import 'package:analyzer/src/generated/source.dart';
  import 'package:unittest/unittest.dart';
  
  import '../../abstract_context.dart';
  
  class AbstractCompletionTest extends AbstractContextTest {
    Index index;
  