public function getUserFlags() : array
    {
        if ($this->flags !== null) {
            return $this->flags;
        }

        $this->flags = [];
        $usergroups = $this->usergroups;

        foreach ($usergroups as $usergroup) {
            $group = $usergroup->group;
            $flags = $group->flags;

            if (!empty($flags)) {
                $this->flags = array_merge($this->flags, $flags);
            }
        }

        return $this->flags;
    }