{"ast_node_type":"variable","tokens":[{"end":84,"kind":"keyword","start":0,"text":"let"}]}
        let mut visitor = GatherLocalsVisitor { fcx, outermost_fn_param_pat: None };
    pub(crate) fn gather_from_arm(fcx: &'a FnCtxt<'a, 'tcx>, local: &'tcx hir::Arm<'tcx>) {
        visitor.visit_pat(local.pat);