test get children test children core factori core factori model core factori creat generaliz element element children object ge core factori creat model core helper children ge size add child object core factori creat gener model core helper set parent ge model core helper set child core factori creat model core helper children ge size add child object core factori creat gener model core helper set parent ge object ge core factori creat model core helper set child ge model core helper children ge size add grandchild object core factori creat gener model core helper set parent ge model core helper set child core factori creat model core helper children ge size 