def store_node(self, node):
        if not self.light.hasAttr(self.message_storage_attr_name):
            pm.addAttr(
                self.light,
                ln=self.message_storage_attr_name,
                m=1
            )

        node.message >> self.light.attr(self.message_storage_attr_name).next_available
stores the node in the storage attribute
dataset/ETHPy150Open eoyilmaz/anima/anima/env/mayaEnv/auxiliary.py/BarnDoorSimulator.store_node