public function getSelectedUser()
    {
        static $user = null;

        if ($user !== null) {
            return $user;
        }

        $staffId = $this->_getIdParam();
        if ($staffId) {
            $user   = $this->loader->getUserLoader()->getUserByStaffId($staffId);
            $source = $this->menu->getParameterSource();
            $user->applyToMenuSource($source);
        } else {
            $user = false;
        }

        return $user;
    }