atk4\data\Join::containsMany PHP Method

    public function containsMany($model, $defaults = [])
    {
        if (!is_array($defaults)) {
            $defaults = [$defaults];
        }
        if (is_string($defaults[0])) {
            $defaults[0] = $this->addField($defaults[0], ['system' => true]);
        }
        return parent::containsMany($model, $defaults);
    }