public async void BookTickerAllOnline()
        {
            var r   = new Maybe <IDownloadData>();
            var b   = new Binance(r);
            var res = await b.BookTicker(new Maybe <string>());

            Assert.NotEmpty(res);
        }
        public async void BookTickerOneSymbolOnline()
        {
            var r   = new Maybe <IDownloadData>();
            var b   = new Binance(r);
            var res = await b.BookTicker(new Maybe <string>("ETHBTC"));

            Assert.Single(res);
        }