yii\mongodb\Query::fetchRowsInternal PHP Method

    protected function fetchRowsInternal($cursor, $all)
    {
        $result = [];
        if ($all) {
            foreach ($cursor as $row) {
                $result[] = $row;
            }
        } else {
            if ($row = current($cursor->toArray())) {
                $result = $row;
            } else {
                $result = false;
            }
        }
        return $result;
    }