anchor.diff:      return context2.test_priorityOrder;
     }
   
  -  void _performPendingAnalysisTasks([int maxTasks = 20]) {
  +  void _performPendingAnalysisTasks([int maxTasks = 512]) {
       for (int i = 0; context.performAnalysisTask().hasMoreWork; i++) {
         if (i > maxTasks) {
           fail('Analysis did not terminate.');
  
positive.code:     expect(info, isNotNull);
    }
  
    Future fail_computeResolvedCompilationUnitAsync_afterDispose() {
      Source source = addSource("/lib.dart", "library lib;");
      // Complete all pending analysis tasks and flush the AST so that it won't
      // be available immediately.
  
negative.code:     expect(resolvedUnit, same(parsedUnit));
    }
  
    Future test_computeResolvedCompilationUnitAsync_dispose() {
      Source source = addSource("/lib.dart", "library lib;");
      // Complete all pending analysis tasks and flush the AST so that it won't
      // be available immediately.
      _performPendingAnalysisTasks();
      _flushAst(source);
      bool completed = false;
      CancelableFuture<CompilationUnit> future =
          context.computeResolvedCompilationUnitAsync(source, source);
      future.then((CompilationUnit unit) {
        fail('Future should have completed with error');
      }, onError: (error) {
  