anchor.diff:  import 'dart:crypto';
   import 'dart:utf';
  +import 'dart:uri';
  +import 'dart:io';
   import 'package:intl/intl.dart';
   
   final DateFormat AWSDATE = new DateFormat('yyyyMMdd');
  
positive.code:   }
  }
  
  
  void main() {
    AwsKey key = new AwsKey();
  
negative.code:   
    print('f4780e2d9f65fa895f9c67b32ce1baf0b0d8a43505a000a1a9e090d414db404d');
    print(key);
    
    var request = new AwsCanonicalRequest();
    request.metode = 'post';
    request.path = '/';
    
    print(request);
    print('---end of request---');
  }
  