Save Multiple GameObject with XML

I really puzzled with http://www.unifycommunity.com/wiki/index.php?title=Save_and_Load_from_XML

From this script. how to this script could save / load array of game objects positions ? And how to make the used objects disappear while loading this scene (from loadXML) ? when i change the _player : GameObject; to _player : GameObject[]; it happen NullReferenceException: Object reference not set to an instance of an object.

Please i really need this function. Thanks for the answer