Call a redis script with keys and args

        The first time we call a script, we register it to speed up later calls.
        We expect a dict with a ``lua`` key having the script, and the dict will be
        updated with a ``script_object`` key, with the content returned by the
        the redis-py ``register_script`` command.

        Parameters
        ----------
        script_dict: dict
            A dict with a ``lua`` entry containing the lua code. A new key, ``script_object``
            will be added after that.
        keys: list of str
            List of the keys that will be read/updated by the lua script
        args: list of str
            List of all the args expected by the script.

        Returns
        -------
        Anything that will be returned by the script

def call_script(self, script_dict, keys=None, args=None):
        """Call a redis script with keys and args

        The first time we call a script, we register it to speed up later calls.
        We expect a dict with a ``lua`` key having the script, and the dict will be
        updated with a ``script_object`` key, with the content returned by the
        the redis-py ``register_script`` command.

        Parameters
        ----------
        script_dict: dict
            A dict with a ``lua`` entry containing the lua code. A new key, ``script_object``
            will be added after that.
        keys: list of str
            List of the keys that will be read/updated by the lua script
        args: list of str
            List of all the args expected by the script.

        Returns
        -------
        Anything that will be returned by the script

        """
        if keys is None:
            keys = []
        if args is None:
            args = []
        if 'script_object' not in script_dict:
            script_dict['script_object'] = self.connection.register_script(script_dict['lua'])
        return script_dict['script_object'](keys=keys, args=args, client=self.connection)