anchor.diff:        // validation and create change
         finalStatus = await refactoring.checkFinalConditions();
         if (_hasFatalError) {
  -        return _sendResultResponse();
  +        _sendResultResponse();
  +        return;
         }
         // simulate an exception
         if (test_simulateRefactoringException_change) {
  
positive.code:     if (refactoring == null) {
        initStatus =
            new RefactoringStatus.fatal('Unable to create a refactoring');
        return;
      }
      // check initial conditions
      initStatus = await refactoring.checkInitialConditions();
  
negative.code:         this.file == file &&
          this.offset == offset &&
          this.length == length) {
        return null;
      }
      _reset();
      this.kind = kind;
  