Retrieve the signed data. If it is expired, it will throw an exception
        :param data: token/signed data
        :param url_safe: bool. If true it will allow it to be passed in URL
        :return: mixed, the data in its original form

def unsign_data(self, data, url_safe=True):
        """
        Retrieve the signed data. If it is expired, it will throw an exception
        :param data: token/signed data
        :param url_safe: bool. If true it will allow it to be passed in URL
        :return: mixed, the data in its original form
        """
        if url_safe:
            return utils.unsign_url_safe(data,
                                         secret_key=self.secret_key,
                                         salt=self.user_salt)
        else:
            return utils.unsign_data(data,
                                     secret_key=self.secret_key,
                                     salt=self.user_salt)