anchor.diff:    tappy_chicken = buildDemo rec {
       name = "ue4demos-tappy_chicken";
       src = fetchurl {
  -      url = "http://ue4linux.raxxy.com/tappy_chicken.zip";
  +      urls = urls "tappy_chicken.zip";
         sha256 = "0lwhvk3lpb2r5ng2cnzk7fpjj5lwhy2sch1a8v154x1xfhfb3h4v";
       };
     };
  
positive.code:   strategy_game = buildDemo rec {
      name = "ue4demos-strategy_game";
      src = fetchurl {
        url = "http://ue4linux.raxxy.com/strategy_game.zip";
        sha256 = "1p7i966v1ssm20y12g4wsccpgnky3szy19qyjlacynk7bgbk6lg7";
      };
    };
  
negative.code:   vehicle_game = buildDemo rec {
      name = "ue4demos-vehicle_game";
      src = fetchurl {
        urls = urls "vehicle_game.zip";
        sha256 = "03dlacf1iv7sgn7pl3sx9r6243wy8fsi2kd858syfm9slg0190bs";
      };
    };
  