Coupon constructor
Coupon({})
Implementation
Coupon({
this.id,
this.object,
this.amountOff,
this.created,
this.currency,
this.duration,
this.durationInMonths,
this.livemode,
this.maxRedemptions,
this.metadata,
this.name,
this.percentOff,
this.redeemBy,
this.timesRedeemed,
this.valid,
});