anchor.diff:  |      Roger M. Needham                                    |
   |                                                          |
   | Code Author: Ma Bingyao <mabingyao@gmail.com>            |
  -| LastModified: Mar 29, 2020                               |
  +| LastModified: Mar 11, 2021                               |
   |                                                          |
   \*________________________________________________________*/
   library xxtea;
  
positive.code:       return data;
      }
      return _toUint8List(
          _encryptUint32List(_toUint32List(data, includeLength), _toUint32List(_fixkey(key), false)), false);
    }
  
    String? encryptToString(dynamic data, dynamic key, {bool includeLength = true}) {
      final encrypted = encrypt(data, key, includeLength: includeLength);
  
      if (encrypted != null) {
  
negative.code:   }
  
    int _mx(int sum, int y, int z, int p, int e, Uint32List k) {
      return ((z >> 5 ^ y << 2) + (y >> 3 ^ z << 4)) ^
          ((sum ^ y) + (k[p & 3 ^ e] ^ z));
    }
  
    Uint8List _fixkey(Uint8List key) {
  