public function postPermissionSource() {
		if ($this->owner->MyPermSourceID) {
			return $this->owner->MyPermSource();
		}

		$source = new PermissionParent();
		$source->Title = 'Posts for ' . $this->owner->getTitle();
		
		$owner = $this->owner;
		
		$this->transactionManager->run(function () use($source, $owner) {
			$source->write();
			$owner->MyPermSourceID = $source->ID;
			$owner->write();
		}, $owner);
		
		return $source;
	}