public function GetKeyMaps($objectclass)
	{
		// TODO: if a php memory error occurs within this method, uncomment this block to debug
		/*
		if (Phreezer::$cnt++ > 500)
		{
			throw new Exception("A sanity limit was exceeded when recursing KeyMaps for `$objectclass`.  Please check your Map for circular joins.");
		}
		//*/

		// this is a temporary ram cache
		$kms = $this->_mapCache->Get($objectclass."KeyMaps");
		if ($kms) return $kms;

		$this->IncludeModel($objectclass);
		if (!class_exists($objectclass."Map")) throw new Exception("Class '" . $objectclass."Map' is not defined.");
		$kms = call_user_func( array($objectclass."Map","GetKeyMaps") );

		$this->_mapCache->Set($objectclass."KeyMaps",$kms);
		return $kms;
	}