static void Main(string[] args)
{
var builder = new CustomerBuilder();
builder.AssignCustomerNumber(321123)
.AssignFirstName("Dude")
.AssignLastName("McGuy");
//preform action to get/calculate age from elsewhere
var age = 22;
builder.AssignAge(age);
var customer = builder.Build();
Console.WriteLine(customer.ToString());
}
