> If you want the same phone number, then you need to use the same one, not a new instance. Generally
you would need to query it.
> If the EJB is a remote bean, then you would need to first find the phone number and call merge in the
create customer instead of persist.
> In general, objects like a phone number are normally not worth sharing, and each Customer would have a OneToMany to a dependent set of phone numbers.