Returning nested object with hasMany relation

[Frederic Visticot]

I would like to have the following data model:

1 Coupon 

1 Coupon template (to store common values of all coupons like image, max number of points)

When creating a coupon the id of the template is stored on the Coupon side

couponTemplate.hasMany(coupon);

Coupon model is successfully created with a CouponTemplateId field.

What do I need to do to find a coupon by ID and returning the nested CouponTemplate. Currenty, only the CouponTemplateId is return in the Coupon object