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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_serializer(self, app: FlaskUnchained, name: str) -> URLSafeTimedSerializer: """ Get a URLSafeTimedSerializer for the given serialization context name. :param app: the :class:`FlaskUnchained` instance :param name: Serialization context. One of ``confirm``, ``login``, ``remember``, or ``reset`` :return: URLSafeTimedSerializer """

        salt = app.config.get('SECURITY_%s_SALT' % name.upper())
        return URLSafeTimedSerializer(secret_key=app.config.SECRET_KEY, salt=salt)