请解释“返回时钟(self.hour,self.minute +分钟)”从这里返回什么?

请说明“返回时钟(self.hour,self.minute +分钟)”从这里返回什么?

class Clock:
    def __init__(self, hour, minute):
        self.hour = ((hour * 60 + minute) % (24 * 60))//60
        self.minute = ((hour * 60 + minute) % (24 * 60)) % 60

    def __repr__(self):
        return "{0:02d}:{1:02d}".format(self.hour, self.minute)

    def __eq__(self, other):
        return self.minute == other.minute and self.hour == other.hour

    def __add__(self, minutes):
        return Clock(self.hour, self.minute + minutes)

    def __sub__(self, minutes):
        return Clock(self.hour, self.minute - minutes)