{"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"impl<'a,"}]}
impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> {
    fn visit_rvalue(&mut self, rvalue: &mir::Rvalue<'tcx>, location: Location) {