anchor.diff:  
   buildPythonPackage rec {
     pname = "exchangelib";
  -  version = "4.6.2";
  +  version = "4.7.0";
     format = "setuptools";
   
  -  disabled = pythonOlder "3.6";
  +  disabled = pythonOlder "3.7";
   
     src = fetchFromGitHub {
       owner = "ecederstrand";
       repo = pname;
       rev = "v${version}";
  -    sha256 = "1vax4xqjav6nr3kfkz390ism3cs69dxnbx6sc0f9ci4mn3rxjwdy";
  +    sha256 = "sha256-APT/esskyigt6u3A+KVTAlmZDMppeyKb9Ws+95hDLcM=";
     };
   
     propagatedBuildInputs = [
  
positive.code:     tzlocal
    ] ++ lib.optionals (pythonOlder "3.9") [
      backports-zoneinfo
    ] ++ lib.optionals (pythonOlder "3.7") [
      backports-datetime-fromisoformat
    ];
  
    checkInputs = [
  
negative.code: { lib
  , backports-zoneinfo
  , buildPythonPackage
  , cached-property
  