public static function importSynonymsFromPlainTextContents(array $synonymFileUpload) : array
    {
        $fileStream = new Stream($synonymFileUpload['tmp_name']);

        $fileLines = GeneralUtility::trimExplode(PHP_EOL, $fileStream->getContents(), true);

        $synonymList = [];
        foreach ($fileLines as $line) {
            $synonymList = self::convertSynonymFileLineForImport($line, $synonymList);
        }

        return $synonymList;
    }