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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove_child_catalogs(self, catalog_id):
 """Removes all children from a catalog. arg: catalog_id (osid.id.Id):
 the ``Id`` of a catalog raise: NotFound - ``catalog_id`` is not in hierarchy raise: NullArgument - ``catalog_id`` is ``null`` raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure occurred *compliance: mandatory -- This method must be implemented.* """

        # Implemented from template for
        # osid.resource.BinHierarchyDesignSession.remove_child_bin_template
        if self._catalog_session is not None:
            return self._catalog_session.remove_child_catalogs(catalog_id=catalog_id)
        return self._hierarchy_session.remove_children(id_=catalog_id)