anchor.diff:  # extras: common
   , bcrypt
   , bleach
  -, flask_mail
  +, flask-mailman
  +, qrcode
   
   # extras: fsqla
   , flask-sqlalchemy
  
positive.code: , peewee
  , pony
  , pytestCheckHook
  , zxcvbn
  }:
  
  
negative.code:     mfa = [
        cryptography
        phonenumbers
      ];
    };
  
  