anchor.diff:      mfa = [
         cryptography
         phonenumbers
  -      pyqrcode
       ];
     };
   
  
positive.code:     peewee
      pony
      pytestCheckHook
      zxcvbn
    ]
    ++ passthru.optional-dependencies.babel
  
negative.code:     common = [
        bcrypt
        bleach
        flask-mailman
        qrcode
      ];
      fsqla = [
        flask-sqlalchemy
  