private async Task UpdateChart()
        {
            this.Stocks.Clear();

            using (var context = new MarketContext())
            {
                foreach (var stock in await context.Stocks.Where(s => s.CompanyId == this.SelectedCompany.Id).ToListAsync())
                {
                    this.Stocks.Add(stock);
                }
            }

            this.ChangeSeriesLegend();
        }
        private async Task InitialLoad()
        {
            List <Company> items = null;

            using (var context = new MarketContext())
            {
                items = await context.Companies.ToListAsync();
            }

            this.Companies.Clear();

            foreach (var company in items)
            {
                this.Companies.Add(company);
            }

            if (this.Companies.Count != 0)
            {
                this.SelectedCompany = this.Companies[0];
            }
        }