anchor.diff:    checkInputs = [
       hypothesis
       pytestcache
  -    pytestflakes
  -    pytestpep8
       pytest
       glibcLocales
     ]
  
positive.code:   # testing based on project's tox.ini
    checkPhase = ''
      pytest --doctest-modules natsort
      pytest --flakes --pep8
    '';
  
    meta = {
  
negative.code: , fetchPypi
  , hypothesis
  , pytestcache
  , pytest
  , glibcLocales
  , mock ? null
  