def __get__(self, instance, owner):
        if instance is None:
            return self

        # instance resources
        instance_namespace = vars(instance)
        instance_ident = instance.name

        # gets from instance namespace
        if self.name in instance_namespace:
            return instance_namespace[self.name]

        # gets from app config (or default value)
        config_name = '{0}_{1}'.format(instance_ident, self.name).upper()
        if current_app.config not in config_name:
            if self.default is not self._missing:
                return self.default
            exception_message = (
                '{0!r} missing {1} \n\n You need to provide it in arguments'
                ' `{0.__class__.__name__}(..., {1}="foobar", ...)` or in '
                'app.config `{2}`').format(instance, self.name, config_name)
            raise RuntimeError(exception_message)
        return current_app.config[config_name]
dataset/ETHPy150Open lepture/flask-oauthlib/flask_oauthlib/contrib/client/descriptor.py/OAuthProperty.__get__/swapped operands of `not in`