public void RentVideo(VideoBefore video, CustomerBefore customer)
 {
     customer.Videos.Add(video);
 }
 public decimal CalculateBalance(CustomerBefore customer)
 {
     return(customer.LateFees.Sum());
 }
 public decimal CalculateBalance(CustomerBefore customer)
 {
     return customer.LateFees.Sum();
 }
 public void RentVideo(VideoBefore video, CustomerBefore customer)
 {
     customer.Videos.Add(video);
 }