constructor(options) {
        if (options.keyv) {
            if (!options.keyv.namespace) {
                console.warn('The given Keyv object has no namespace. This is a bad idea if you share a database.');
            }
            this.conversationsCache = options.keyv;
        } else {
            const cacheOptions = options.cache || {};
            cacheOptions.namespace = cacheOptions.namespace || 'bing';
            this.conversationsCache = new Keyv(cacheOptions);
        }

        this.setOptions(options);
    }
https://stackoverflow.com/a/58326357
@param {number} size