Updating related records

I'm trying to implement an update to related records. I've read the documentation regarding this feature (available here: https://docs.phalcon.io/en/latest/reference/models.html#updating-related-records)

I'm using Phalcon 1.2.3 and I get the following error when calling the update method:

Call to undefined method Phalcon\Mvc\Model\Resultset\Simple::update()

My (simplified) code is:

public function afterSave() {
    $this->getRelatedRecords()->update(array('column' => 'value');
}

Shouldn't this method be available on Phalcon 1.2.3?

Thank you.