anchor.diff:  { lib
   , brotli
  +, brotlicffi
   , buildPythonPackage
  +, certifi
   , cryptography
   , python-dateutil
   , fetchPypi
  +, isPyPy
   , idna
  -, isPy27
   , mock
   , pyopenssl
   , pysocks
  
positive.code:     "urllib3"
    ];
  
    meta = with lib; {
      description = "Powerful, sanity-friendly HTTP client for Python";
      homepage = "https://github.com/shazow/urllib3";
  
negative.code:     hash = "sha256-qrrxZHeAal4d0ZqkH4wreVDdPHRjYtfjIj2+beasRI4=";
    };
  
    # FIXME: remove backwards compatbility hack
    propagatedBuildInputs = passthru.optional-dependencies.brotli
      ++ passthru.optional-dependencies.secure;
  
    checkInputs = [
      python-dateutil
  