{"ast_node_type":"function","tokens":[{"end":46,"kind":"keyword","start":0,"text":"fn"}]}
        fn check_for_self_assign_helper<'tcx>(
    fn check_for_self_assign(&mut self, assign: &'tcx hir::Expr<'tcx>) {
            typeck_results: &'tcx ty::TypeckResults<'tcx>,