public function lock($member = null) {
		if (!$member) {
			$member = Member::currentUser();
		}

		// set the updated lock expiry based on now + lock timeout
		$this->WikiLastEditor = $member->Email;
		$this->WikiLockExpiry = date('Y-m-d H:i:s', time() + $this->config()->get('lock_time'));

		// save it with us as the editor
		$this->write();
	}