{"type":"Feature","properties":{"what":"no id again"},"geometry":{"type":"Point","coordinates":[0,0]}}
{"type":"Feature","id":12346,"properties":{"what":"will be lost as a duplicate"},"geometry":{"type":"Point","coordinates":[0,0]}}
{"type":"Feature","id":12347,"properties":{"what":"will be added"},"geometry":{"type":"Point","coordinates":[0,0]}}