Remove an item altogether by setting link_list to None.
        Currently, only links can contain multiple children of the same type.
        :param link_type:
        :param link_set:
        :return:

def upsert_link_set(self, link_type, link_set):
        """
        Remove an item altogether by setting link_list to None.
        Currently, only links can contain multiple children of the same type.
        :param link_type:
        :param link_set:
        :return:
        """
        if link_set is None:
            self.links.pop(link_type, None)
            return
        links = copy.deepcopy(self.links)
        links.update({link_type: link_set})
        self.links = links