{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
                    let (category, from_closure, span, region_name, path) =
                if let Some(region) = self.to_error_region_vid(borrow_region_vid) {
                        self.free_region_constraint_info(borrow_region_vid, region);