{"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"Ok(FallibleTypeFolder::cx(folder).mk_external_constraints(ExternalConstraintsData"}]}
        Ok(FallibleTypeFolder::cx(folder).mk_external_constraints(ExternalConstraintsData {
            region_constraints: self.region_constraints.clone().try_fold_with(folder)?,