static async Task GetPortfolios()
        {
            using (RobinhoodClient client = new RobinhoodClient(_token))
            {
                var resultPortfolios = await client.Portfolios();

                if (resultPortfolios.StatusCode == System.Net.HttpStatusCode.OK)
                {
                    resultPortfolios.Data.Results.ForEach(portfolio =>
                                                          Console.WriteLine(portfolio.MarketValue)
                                                          );
                }

                //by accountNumber
                var resultPortfolio = await client.Portfolios(UrlManager.GetAccountNumber(_account));

                if (resultPortfolio.StatusCode == System.Net.HttpStatusCode.OK)
                {
                    Console.WriteLine(resultPortfolio.Data.MarketValue);
                }
            }
        }