anchor.diff:      subPackages = [
         "."
       ];
  -    date = "2016-12-13";
  +    date = "2016-12-27";
     };
   
     lemma = buildFromGitHub {
  
positive.code: 
    google-cloud-go = buildFromGitHub {
      version = 2;
      date = "2016-12-19";
      rev = "3c4c8cc11d151d76587802cb55dd7b80beca832b";
      owner = "GoogleCloudPlatform";
      repo = "google-cloud-go";
      sha256 = "1zsggnkg1vk1c2z6ljk2w5gsj8g212d249hlkf04kydyr044a5dq";
      goPackagePath = "cloud.google.com/go";
      goPackageAliases = [
        "google.golang.org/cloud"
  
negative.code: 
    tablewriter = buildFromGitHub {
      version = 2;
      rev = "44e365d423f4f06769182abfeeae2b91be9d529b";
      date = "2016-12-29";
      owner  = "olekukonko";
      repo   = "tablewriter";
      sha256 = "129zcc9k2xxs16lhv7ncg07b2glfrjzks6rna2zl9ss60q03r6ym";
      propagatedBuildInputs = [
        go-runewidth
      ];
  