{"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"while"}]}
                    while let MacroRulesScope::Invocation(invoc_id) = macro_rules_scope.get() {
                    // scopes for macros that were already expanded.
                        if let Some(next_scope) = self.output_macro_rules_scopes.get(&invoc_id) {