{"ast_node_type":"variable","tokens":[{"end":98,"kind":"keyword","start":0,"text":"let"}]}
                let outlived_fr_region_name = self.give_region_a_name(errci.outlived_fr).unwrap();
                fr_region_name.highlight_region_name(&mut diag);
                outlived_fr_region_name.highlight_region_name(&mut diag);