public function updateCMSFields(FieldList $fields) {
		$excluded = $this->owner->getExcludedSiteTreeClassNames();
		if(!empty($excluded)) {
			$pages = SiteTree::get()->filter(array(
				'ParentID' => $this->owner->ID,
				'ClassName' => $excluded
			));
			$gridField = new GridField(
				"ChildPages",
				$this->getLumberjackTitle(),
				$pages,
				GridFieldConfig_Lumberjack::create()
			);

			$tab = new Tab('ChildPages', $this->getLumberjackTitle(), $gridField);
			$fields->insertAfter($tab, 'Main');
		}
	}