public static Monetary Total(ILineCalculable lineCalculable)
 {
     return(SubTotal(lineCalculable) + TaxTotal(lineCalculable));
 }
 public static Monetary SubTotal(ILineCalculable lineCalculable)
 {
     return(lineCalculable.Price * lineCalculable.Quantity);
 }
 public static Monetary TaxTotal(ILineCalculable lineCalculable)
 {
     return(SubTotal(lineCalculable) * lineCalculable.TaxRate);
 }