def add_aggregate(self, xml_var, obj):
		self.get_aggregate_list(xml_var).append(obj)
		self.aggregate_order.append(obj)
		self.aggregate_type[obj] = xml_var
NOTE: One must keep careful track of aggregate types for this system.
dataset/ETHPy150Open RobotLocomotion/director/src/python/urdf_parser_py/xml_reflection/core.py/Object.add_aggregate