def update(self, mapping, prefix=""):
        """
        Set the values of multiple keys at once.

        :param dict mapping: Mapping of keys to values
        :param str prefix: Optional prefix to apply to all keys in `mapping`
            before setting
        """
        for k, v in mapping.items():
            self.set("%s%s" % (prefix, k), v)
Set the values of multiple keys at once.

        :param dict mapping: Mapping of keys to values
        :param str prefix: Optional prefix to apply to all keys in `mapping`
            before setting