anchor.diff:                     Uri.encodeQueryComponent(value)]));
       return pairs.map((pair) => "${pair[0]}=${pair[1]}").join("&");
     }
  -  
  +
     SecureRandom getSecureRandom(){
         return new NullSecureRandom();
       }
  
positive.code:       return signature.bytes;
      });
    }
   
  
    String _mapToQuery(Map<String, String> map, {Encoding encoding}) {
      var pairs = <List<String>>[];
  
negative.code:   Map clain;
    Map auth;
    int iat;
  
    String get accessToken => auth["access_token"];
  
    JWT(String iss, String scopes){
      header = {"alg":"RS256","typ":"JWT"} ;
      DateTime now = new DateTime.now();
  