anchor.diff:    int _bitBuffer = 0;
     int _bitPos = 0;
   
  -  static const List<int> _BIT_MASK = const [0, 1, 2, 4, 8, 16, 32, 64, 128];
  -  static const List<int> _BIT_MASK2 = const [0, 1, 3, 7, 15, 31, 63, 127, 255];
  +  static const List<int> _BIT_MASK = const [0, 1, 3, 7, 15, 31, 63, 127, 255];
   }
  
positive.code:       }
  
        value = (value << numBits) +
                (_bitBuffer >> (_bitPos - numBits) & _BIT_MASK2[numBits]);
  
        _bitPos -= numBits;
      }
  
negative.code:     int value = 0;
  
      while (numBits > _bitPos) {
        value = (value << _bitPos) + (_bitBuffer & _BIT_MASK[_bitPos]);
        numBits -= _bitPos;
        _bitPos = 8;
        _bitBuffer = input.readByte();
  