<parttree><part partid="0" name="car"><part partid="1" name="engine"><part partid="3" name="piston"/></part><part partid="2" name="door"><part partid="4" name="window"/><part partid="5" name="lock"/></part></part><part partid="10" name="skateboard"><part partid="11" name="board"/><part partid="12" name="wheel"/></part><part partid="20" name="canoe"/></parttree>