class Member {

    public void setCoupons(List<Coupon> coupons) {
        this.coupons = coupons;
    }

}

class MemberTest {

    @Test
    public void test_01() {


        final Member member = new Member("asd@asd.com", "name");
        final Coupon coupon = new Coupon(member);
        final List<Coupon> coupons = new ArrayList<>();
        coupons.add(coupon);
        member.setCoupons(coupons);

        System.out.println(member.toString());
    }

}