anchor.diff:  
     DirectoryLister lister = dir.list(recursive:true);
   
  -  lister.onError = (e) => print(e);
  +  lister.onError = (e) {
  +    print('an error occured while listing the directory:\n $e');
  +  };
     lister.onDir  = (String dir) {
       if (projectPath == dir) {
         existing = new File(dir);
  
positive.code: 
  Future<bool> prompt(String message) {
    print('$message[y/n]');
  
    Completer completer = new Completer();
  
    StringInputStream stream = new StringInputStream(stdin);
    stream.onLine = () {
      String answer = stream.readLine().toLowerCase().trim();
  
negative.code: 
         Future<bool> webFuture = prompt('generate content for a base web app?');
         webFuture.then((bool value) {
           if (value == true) {
             createDirectory('${projectPath}/web').then((Directory dir) {
               if (dir != null) {
                 Future<bool> dartFile = createFile('${projectPath}/web/${projectName}.dart', TEMPLATE_DART_WEB);
  