def mset(self, mapping):
        """
        Sets key/values based on a mapping. Mapping is a dictionary of
        key/value pairs. Both keys and values should be strings or types that
        can be cast to a string via str().
        """
        items = []
        for pair in iteritems(mapping):
            items.extend(pair)
        return self.execute_command('MSET', *items)