public function getAttributesValues(array $cells)
    {
        $result = [];
        foreach ($this->fieldsMap as $cellIndex => $info) {
            switch ($info['kind']) {
                case 'singleAttributeHeader':
                    $attributeIndex = $info['attributeIndex'];
                    $result[$attributeIndex] = isset($cells[$cellIndex]) ? $cells[$cellIndex] : '';
                    break;
                case 'multipleAttributeHeader':
                    $attributeIndex = $info['attributeIndex'];
                    $attributeSubHeader = $info['attributeSubHeader'];
                    $value = isset($cells[$cellIndex]) ? $cells[$cellIndex] : '';
                    if (isset($result[$attributeIndex])) {
                        $result[$attributeIndex][$attributeSubHeader] = $value;
                    } else {
                        $result[$attributeIndex] = [$attributeSubHeader => $value];
                    }
                    break;
            }
        }

        return $result;
    }