在一种情况下,new(0,0)被分配给常量CLOSED.在另一种情况下,new(open,close)是函数的返回值.为什么这样？当它以这种方式使用时,“新”的做法是什么？是什么创造的？

class OpenHours
 
    attr_reader :open,:close
 
    def initialize(open,close)
      @open,@close = open,close
    end
 
    def duration
      @duration ||= @open < @close ? @close - @open : 0
    end
 
    CLOSED = new(0,0)                #first new
 
 
    def self.parse(open,close)
      open  = Time.parse(open)
      close = Time.parse(close)
 
 
      open  = TimeUtils::seconds_from_midnight(open)
      close = TimeUtils::seconds_from_midnight(close)
 
 
      new(open,close)                        #second new
 
    end
 
    def offset(seconds)
      self.class.new([@open,seconds].max,@close)     #third new
    end
 
  end