atk4\data\Model::init PHP Method

    public function init()
    {
        $this->_init();
        if ($this->id_field) {
            $this->addField($this->id_field, ['system' => true]);
        }
    }

 public function init()
 {
     parent::init();
     $this->addField('name');
     $this->addField('surname');
     $this->addField('gender', ['enum' => ['M', 'F']]);
 }