protected function prepareInsertData(array $data)
    {
        $dbData       = [];
        $extraColumns = $this->extraColumns ? $this->extraColumns : [];

        foreach ($data as $key => $value) {
            $dbData[] = array_merge($extraColumns, [
                $this->keyColumn   => $key,
                $this->valueColumn => $value,
            ]);
        }

        return $dbData;
    }