anchor.diff:    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();
  
positive.code:     }
      return CURRENT;
    }
    
    Map<String, RSAPrivateKey> iss_privateKeys = {};
    Map<String, Map<String, JWT>> _store = {};
       
    void registerKey(String isss, String pemkey, {String password}){
      rsa_pkcs.RSAPKCSParser parser = new rsa_pkcs.RSAPKCSParser();
      rsa_pkcs.RSAPrivateKey pk = parser.parsePEM(pemkey, password:password).private;
      RSAPrivateKey privk = new RSAPrivateKey(pk.modulus, pk.privateExponent, pk.prime1, pk.prime2);
      iss_privateKeys[isss]=privk;
      _store[isss] = {}; 
    }
    
    Future<JWT> generateJWT(String isss , String scopes){
      JWT jwt;
      if (_store[isss].containsKey(scopes)){
  
negative.code:                  "exp":exp,
                   "iat":iat};
    }
  
    bool get isExpired {
      DateTime now = new DateTime.now();
      return iat >= auth["expires_in"] + (now.millisecondsSinceEpoch ~/ 1000);
    }
  
    Future generateAuth(String privateKeyFile){
      return _generateJWT(privateKeyFile).then((jwt){
        Map map = {"grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
  