@abc.abstractmethod<EOL><INDENT>def get_child_repository_ids(self, repository_id):<DEDENT>
return<EOL>
Gets the ``Ids`` of the children of the given repository.

        :param repository_id: the ``Id`` to query
        :type repository_id: ``osid.id.Id``
        :return: the children of the repository
        :rtype: ``osid.id.IdList``
        :raise: ``NotFound`` -- ``repository_id`` not found
        :raise: ``NullArgument`` -- ``repository_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*