in version 1.19 , the player 's attachment to the object stopped working.
dta\scripts\1_Core\proto\EnEntity.c
proto native external bool AddChild(notnull IEntity child, int pivot, bool positionOnly = false);
dta\scripts\3_Game\human.c
proto native void LinkToLocalSpaceOf(notnull IEntity child, vector pLocalSpaceMatrix[4]);