how & where to define addHasMany relation ship

https://docs.phalcon.io/ru/latest/reference/models.html#id12

addHasMany is an abstract method defined in interface model, I want to know the usage and where to define it

addHasMany is not an abstract method defined in interface model: https://docs.phalcon.io/en/latest/api/Phalcon_Mvc_ModelInterface.html#methods

sorry for mistake check link to see addHasMany method https://docs.phalcon.io/en/latest/api/Phalcon_Mvc_Model_Manager.html

This is the usage: https://github.com/phalcon/cphalcon/blob/2.0.0/phalcon/mvc/model.zep#L3471-L3497

I was not able to find addHasMany method useage there

Thank you very much for the explanation!

<?php
class Robots extends \Phalcon\Mvc\Model
{

  public function initialize()
  {
      $this->_modelsManager->addHasMany($this, 'id', 'RobotsParts', 'robots_id', null);
  }

}

getting error

[Wed, 10 Sep 14 10:21:35 +0200][ERROR] [2] Phalcon\Mvc\Model\Manager::addHasMany(): phalcon_get_class expects an object ( Line: [99])