How to summon an entity next to another entity?

So, I googled this question and I didn't find a soluton to this problem.

Never mind, I have found a solution
It is:
if (event.getEntityType() == EntityType.VILLAGER) {
Zombie zomb = event.getEntity().getWorld().spawn(event.getEntity().getLocation().add(0,0,0), Zombie.class);
}

EDIT by Moderator: merged posts, please use the edit button instead of double posting.