anchor.diff:  { lib
   , buildPythonPackage
   , fetchFromGitHub
  +, freezegun
   , mock
   , nose2
   , pytz
  
positive.code:   ];
  
    checkInputs = [
      mock
      nose2
      pytz
  
negative.code: 
  buildPythonPackage rec {
    pname = "duo-client";
    version = "4.5.0";
  
    src = fetchFromGitHub {
      owner = "duosecurity";
      repo = "duo_client_python";
      rev = version;
      sha256 = "sha256-9ADFtCrSJ4Y2QQY5YC/BMvoVZs2vaYHkhIM/rBlZm4I=";
    };
  
    postPatch = ''
  