private function validateShareRequest(array $shareRequest)
    {
        $errors = [];

        if (empty($shareRequest['questions']) || !is_array($shareRequest['questions'])) {
            $errors[] = [
                'path' => '/questions',
                'message' => 'should be a list of question ids',
            ];
        }

        if (empty($shareRequest['users']) || !is_array($shareRequest['users'])) {
            $errors[] = [
                'path' => '/users',
                'message' => 'should be a list of user ids',
            ];
        }

        if (!is_bool($shareRequest['adminRights'])) {
            $errors[] = [
                'path' => '/adminRights',
                'message' => 'should be boolean',
            ];
        }

        return $errors;
    }