anchor.diff:  , pytz
   , tornado
   , prometheus_client
  +, pytestCheckHook
   }:
   
   buildPythonPackage rec {
     pname = "flower";
  -  version = "0.9.7";
  +  version = "1.0.0";
   
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "cf27a254268bb06fd4972408d0518237fcd847f7da4b4cd8055e228150ace8f3";
  +    sha256 = "1gcczr04g7wx99h7pxxx1p9n50sbyi0zxrzy7f7m0sf5apxw85rf";
     };
   
     postPatch = ''
       # rely on using example programs (flowers/examples/tasks.py) which
       # are not part of the distribution
       rm tests/load.py
  -    substituteInPlace  requirements/default.txt --replace "prometheus_client==0.8.0" "prometheus_client>=0.8.0"
     '';
   
     propagatedBuildInputs = [
  
positive.code:     prometheus_client
    ];
  
    checkInputs = [ mock ];
  
    pythonImportsCheck = [ "flower" ];
  
  
negative.code:     description = "Celery Flower";
      homepage = "https://github.com/mher/flower";
      license = licenses.bsdOriginal;
      maintainers = with maintainers; [ arnoldfarkas ];
    };
  }
  