Doctrine ORM payments are becoming delusional —
So, the transaction payer is association, whereas collection is the payee.
How come? See the code (besides official ORM documentation):
/*** Notes collection** @var ArrayCollection** @ORM\OneToMany(targetEntity="Note", mappedBy="user")*/private $_notes;
The entity is having property of
ArrayCollection type, which contains association paid money, i.e. variable array of entity object format.