Conventional way to add methods to a class

conventional_class_reopening.rb

class Cart
  def confirm
    "Your order is being processed"
  end
end

cart = Cart.new
# then reopen the class

class Cart
  def deny
    "Your order has been denied!"
  end
end
cart.deny
#=> "Your order has been denied!" 

next_cart = Cart.new
next_cart.deny
#=> "Your order has been denied!"