def sunionstore(self, dest, keys, *args):
        """
        Store the union of sets specified by ``keys`` into a new
        set named ``dest``.  Returns the number of keys in the new set.
        """
        args = list_or_args(keys, args)
        return self.execute_command('SUNIONSTORE', dest, *args)

        Store the union of sets specified by ``keys`` into a new
        set named ``dest``.  Returns the number of keys in the new set.
        
stackoverflow/venv/lib/python3.6/site-packages/redis/client.py