<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def register_transfer(self, relation, old_id, new_id):
 """Register the old and new ids for a particular record in a relation."""

    transfer = Transfer(relation_id=relation.id, old_id=old_id, new_id=new_id)
    self.data_access.insert_model(transfer)
    return transfer