public function render($format = 'initials')
    {
        if (!in_array($format, ['fullFirstName', 'initials', 'fullName'])) {
            throw new \InvalidArgumentException(sprintf('Format "%s" given to backend.userInitials(), only supporting "fullFirstName", "initials" and "fullName".', $format), 1415705861);
        }

        $username = $this->renderChildren();

        /* @var $requestedUser Person */
        $requestedUser = $this->domainUserService->getUser($username);
        if ($requestedUser === null || $requestedUser->getName() === null) {
            return $username;
        }

        $currentUser = $this->userService->getBackendUser();
        if ($currentUser) {
            if ($currentUser === $requestedUser) {
                $translationHelper = new TranslationHelper();
                $you = $translationHelper->translate('you', null, [], 'Main', 'Neos.Neos');
            }
        }

        switch ($format) {
            case 'initials':
                return mb_substr(preg_replace('/[^[:alnum:][:space:]]/u', '', $requestedUser->getName()->getFirstName()), 0, 1) . mb_substr(preg_replace('/[^[:alnum:][:space:]]/u', '', $requestedUser->getName()->getLastName()), 0, 1);
            case 'fullFirstName':
                return isset($you) ? $you : trim($requestedUser->getName()->getFirstName() . ' ' . ltrim(mb_substr($requestedUser->getName()->getLastName(), 0, 1) . '.', '.'));
            case 'fullName':
                return isset($you) ? $you : $requestedUser->getName()->getFullName();
        }
    }