anchor.diff:        pgpKeyFingerprints = [
           "DD8F 2338 BAE7 501E 3DD5  AC78 C273 792F 7D83 545D"
           "B9AE 9905 FFD7 803F 2571  4661 B63B 535A 4C20 6CA9"
  +        "FD3A 5288 F042 B685 0C66  B31F 09FE 4473 4EB7 990E"
         ];
         inherit (src) urls outputHash outputHashAlgo;
       };
  
positive.code:   src = fetchurl {
      urls = map (n: "${n}/node-v${version}.tar.xz") dirUrls;
      allowHashOutput = false;
      sha256 = "2dfeeddba750b52a528b38a1c31e35c1fb40b19cf28fbf430c3c8c7a6517005a";
    };
  
    nativeBuildInputs = [
  
negative.code: }:
  
  let
    version = "6.3.0";
  
    dirUrls = [
      "https://nodejs.org/dist/v${version}"
  