yii\twig\Extension::endWidget PHP Method

    public function endWidget($widget = null)
    {
        if ($widget === null) {
            if (empty($this->widgets)) {
                throw new InvalidCallException('Unexpected end_widget() call. A matching begin_widget() is not found.');
            }
            $this->call(array_pop($this->widgets), 'end');
        } else {
            array_pop($this->widgets);
            $this->resolveAndCall($widget, 'end');
        }
    }