public BranchEvent setCoupon(String coupon) {
        return addStandardProperty(Defines.Jsonkey.Coupon.getKey(), coupon);
    }
public BranchEvent setCoupon ( String coupon ) { return addStandardProperty ( Defines . Jsonkey . Coupon . getKey ( ) , coupon ) ; }
Set any coupons associated with this transaction event

@param coupon {@link String } with any coupon value
@return This object for chaining builder methods