anchor.diff:  
   buildPythonPackage rec {
     pname = "httplib2";
  -  version = "0.20.1";
  +  version = "0.20.3";
  +  format = "setuptools";
   
     src = fetchFromGitHub {
       owner = pname;
       repo = pname;
       rev = "v${version}";
  -    sha256 = "sha256-1zqs3YRVtm5DwewETLtRg5XhMJPJsMi0QLfeGirOURs=";
  +    sha256 = "sha256-Q5KkhVqyHDoIeKjvvYoHRbZPY7LUXGDwgp4CSuyvQ1g=";
     };
   
  -  postPatch = ''
  -    sed -i "/--cov/d" setup.cfg
  -  '';
  -
  -  propagatedBuildInputs = [ pyparsing ];
  -
  -  pythonImportsCheck = [ "httplib2" ];
  -
  -  # Don't run tests for Python 2.7
  -  doCheck = !isPy27;
  +  propagatedBuildInputs = [
  +    pyparsing
  +  ];
   
     checkInputs = [
  +    cryptography
       mock
       pytest-forked
       pytest-randomly
  
positive.code: { lib
  , stdenv
  , buildPythonPackage
  , fetchFromGitHub
  , isPy27
  , mock
  
negative.code:     pytestCheckHook
    ];
  
    # Don't run tests for Python 2.7
    doCheck = !isPy27;
  
    postPatch = ''
      sed -i "/--cov/d" setup.cfg
    '';
  
    disabledTests = lib.optionals (stdenv.isDarwin) [
      # fails with HTTP 408 Request Timeout, instead of expected 200 OK
      "test_timeout_subsequent"
    ];
  
    pytestFlagsArray = [
      "--ignore python2"
    ];
  
    pythonImportsCheck = [
      "httplib2"
    ];
  
    meta = with lib; {
      description = "A comprehensive HTTP client library";
      homepage = "https://github.com/httplib2/httplib2";
      license = licenses.mit;
      maintainers = with maintainers; [ fab ];
    };
  