anchor.diff:  
   main() {
     test.group("arcfour", () {
  -    test.test("operate", () {
  +    test.test("operateA", () {
         List<int> key = Hex.decodeWithNew("0xABCDEF");
         List<int> value = Hex.decodeWithNew("0xA1B2C3D4E5F6A7B8C9");
   //      List<int> result = Hex.decodeWithNew();
  
positive.code:       test.expect(Hex.encodeWithNew(output), "0x91b44728ff906c143d");
      });
  
      test.test("operate", () {
        List<int> key = [0, 0];
        key.addAll(Hex.decodeWithNew("0xABCDEF"));
        List<int> value = [0, 0];
  
negative.code:       ARCFOUR.operate(value, 2, value.length - 2, state, 2, stateIJ, 2, output, 2);
        test.expect(Hex.encodeWithNew(output.sublist(2)), "0x91b44728ff906c143d");
      });
  
      test.test("operateC", () {
        List<int> key = Hex.decodeWithNew("0xA0A1A2A3A4A5A6A7A8A9B0B1B2B3B4B5B6B7B8B9C0C1C2C3C4C5C6C7C8C9D1D2");
        List<int> value = Hex.decodeWithNew("0xA0A1A2A3A4A5A6A7A8A9B0B1B2B3B4B5B6B7B8B9C0C1C2C3C4C5C6C7C8C9D1D2");
  //      List<int> result = Hex.decodeWithNew();
  
        List<int> output = new List(value.length);
        List<int> state = new List(256);
        List<int> stateIJ = [0, 0];
  
        ARCFOUR.makeState(key, 0, key.length, state, 0);
        //print("####### ${Hex.encodeWithNew(state)}");
        ARCFOUR.operate(value, 0, value.length, state, 0, stateIJ, 0, output, 0);
        test.expect(Hex.encodeWithNew(output), "0x07df75ad3257de1b67f19348a8d562923a59d50d947a229272785185ba919788");
      });
    });
  }
  