public function getLanguageNames($locale, $languageCodes)
    {
        if (is_string($languageCodes)) {
            $languageCodes = [$languageCodes];
        }

        /** @noinspection XmlUnusedNamespaceDeclaration */
        $requestXml = '<ArrayOfstring xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">';
        if (sizeof($languageCodes) > 0) {
            foreach ($languageCodes as $codes) {
                $requestXml .= "<string>$codes</string>";
            }
        } else {
            throw new Exception('$languageCodes array is empty.');
        }
        $requestXml .= '</ArrayOfstring>';

        return $this->post('/GetLanguageNames?locale='.$locale, [], $requestXml, true, $languageCodes);
    }