public function write(string $siteIdentifier, array $configuration): void
    {
        $fileName = $this->configPath . '/' . $siteIdentifier . '/' . $this->configFileName;
        if (!file_exists($fileName)) {
            GeneralUtility::mkdir_deep($this->configPath . '/' . $siteIdentifier);
        }
        $yamlFileContents = Yaml::dump($configuration, 99);
        GeneralUtility::writeFile($fileName, $yamlFileContents);
        $this->getCache()->remove($this->cacheIdentifier);
        $this->getCache()->remove('pseudo-sites');
    }