public void RemoveSales(SalesRecord sr)
 {
     SalesRecordy.Remove(sr);
 }
 public double TotalSales(DateTime inital, DateTime final)
 {
     return(SalesRecordy.Where(sr => sr.Date >= inital && sr.Date <= final).Sum(sr => sr.Amount)); // caulcula o total de vendas de um vendedor pelo periodo
 }
 public void AddSales(SalesRecord sr)
 {
     SalesRecordy.Add(sr);
 }