def _get_cache_key(self):
        """
        The cache key is a string of concatenated sorted names and values.
        """

        keys = list(self.params.keys())
        keys.sort()

        cache_key = str()

        for key in keys:
            if key != "api_sig" and key != "api_key" and key != "sk":
                cache_key += key + self.params[key]

        return hashlib.sha1(cache_key.encode("utf-8")).hexdigest()
The cache key is a string of concatenated sorted names and values.