protected function mapFields($data)
    {
        $result = [];
        $index = 0;

        foreach ($this->csvFileFieldsOrder as $value) {
            if (!empty($value)) {
                if (strtolower($data[$index]) == 'null') {
                    $result[$value] = null;
                } else {
                    $result[$value] = $data[$index];
                }
            }
            $index++;
        }

        return $result;
    }