private void ValidateGizmo()
{
if (ProductCode.Substring(1).Length != 3)
{
throw new InvalidException("Gizmo codes must contain 3 digits");
}
}
private void ValidateWidget()
{
if (ProductCode.Substring(1).Length != 4)
{
throw new InvalidException("Widget codes must contain 4 digits");
}
if (Quantity % 1 != 0)
{
throw new InvalidException("Widget are sold by the unit so quantity must be whole number");
}
}
