{"ast_node_type":"variable","tokens":[{"end":58,"kind":"keyword","start":0,"text":"if"}]}
        if let ty::RePlaceholder(placeholder) = r.kind() {
    fn to_region_vid(&mut self, r: ty::Region<'tcx>) -> RegionVid {
            self.constraints.placeholder_region(self.infcx, placeholder).as_var()