anchor.diff:    inherit (lib)
       optionals;
   
  -  version = "3.5.3";
  +  version = "3.6.0";
   in
   buildPythonPackage rec {
     name = "apscheduler-${version}";
  
positive.code:   src = fetchPyPi {
      package = "APScheduler";
      inherit version;
      sha256 = "6599bc78901ee7e9be85cbd073d9cc155c42d2bc867c5cde4d4d1cc339ebfbeb";
    };
  
    propagatedBuildInputs = [
  
negative.code:     tornado
      twisted
      /* job stores */
      #kazoo  # TODO: zookeeper
      pymongo
      redis
      #rethinkdb
  