def _get_list_of_missing_weakrefs(self) -> Set[int]:
        """
        Iterates through the list and checks for weakrefs.

        :return: The set of missing weakref indices
        :rtype: Set[int]
        """
        to_remove = set()
        for ind, relation_child in enumerate(self[:]):
            try:
                relation_child.__repr__.__self__  # type: ignore
            except ReferenceError:  # pragma no cover
                to_remove.add(ind)

        return to_remove

        Iterates through the list and checks for weakrefs.

        :return: The set of missing weakref indices
        :rtype: Set[int]
        
ormar/relations/relation_proxy.py