{"ast_node_type":"variable","tokens":[{"end":72,"kind":"keyword","start":0,"text":"let"}]}
                    let src = self.expander.in_file(AstPtr::new(&node));
                    let macro_ptr = AstPtr::new(&mcall);
                    let id = self.collect_macro_call(mcall, macro_ptr, true, |this, expansion| {