public static function save( $fileName, $data, $packetName = NULL )
	{
		if( $packetName === NULL )
			$wddx	= wddx_serialize_value( $data );
		else
			$wddx	= wddx_serialize_value( $data, $packetName );
		return FS_File_Writer::save( $fileName, $wddx );
	}