public static RedisConfiguration CreateFromString(string connString, int?databaseId = null)
        {
            RedisConfiguration   config = new RedisConfiguration();
            ConfigurationOptions opt    = ConfigurationOptions.Parse(connString);

            config.ConfigOptions = opt;

            if (databaseId.HasValue)
            {
                config.ConfigOptions.DefaultDatabase = databaseId.Value;
            }

            return(config);
        }