{"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"SyntaxExtensionKind::Bang(expander)"}]}
                SyntaxExtensionKind::Bang(expander) => {
            InvocationKind::Bang { mac, span } => match ext {
                    match expander.expand(self.cx, span, mac.args.tokens.clone()) {