{"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"NllRegionVariableOrigin::Placeholder(placeholder)"}]}
                        NllRegionVariableOrigin::Placeholder(placeholder) => {
                            .map(|ur| self.definitions[ur].external_name.unwrap()),
                            Some(ty::Region::new_placeholder(infcx.tcx, placeholder))