class Record
def add_record
raise 'Abastract method'
end
end
class Event < Record
def add_record
puts '增加一条日志'
end
end
class OrderEvent < Record
attr_accessor :event
def initialize
@event = Event.new
end
def add_record
puts '给订单'
@event.add_record
end
end
OrderEvent.new.add_record