Adding a method to eigenclass doesn't work properly. Works in cruby #596

 class X
  def total_cost 
    99
  end
  alias_method :old_dup, :dup
  def dup
    c = self.old_dup
    class << c
      attr_reader :total_cost
      public
      def initialize_copy(orig)
        puts "Inside initialize_copy"
        @total_cost = orig.total_cost
      end
    end
    c.initialize_copy(self)
    return c
  end
end

 an_x = X.new
 an_x.dup