anchor.diff:  
     roaring = buildFromGitHub {
       version = 3;
  -    rev = "v0.3.15";
  +    rev = "v0.3.16";
       owner  = "RoaringBitmap";
       repo   = "roaring";
  -    sha256 = "0rpqd6jcf1pk4q219r3q21pi1wscr2m6ylh93s3wzb0pr2rap209";
  +    sha256 = "125vrshk7a09w0q6171hlng0z6xvlk74qcxl7bw0dygl62w48gs5";
       propagatedBuildInputs = [
         go-unsnap-stream
         msgp
  
positive.code:       inherit
          goPackagePath
          rev;
        date = "2017-11-05";
      };
      rev = "db5825e00e9e1e4c36e40a5fe0b23fe8fe08d458";
      goPackagePath = "google.golang.org/api";
      src = fetchzip {
        version = 3;
  
negative.code: 
    govalidator = buildFromGitHub {
      version = 3;
      rev = "635ecdbba9da0d6d1ac71d2d36588b899a318a89";
      owner = "asaskevich";
      repo = "govalidator";
      sha256 = "0483f3zb45xfv1kkl51jr7dj2ky8zjl49z74pdp57dz8aiahrp9h";
      date = "2017-11-09";
    };
  
    goversion = buildFromGitHub {
  