{"ast_node_type":"variable","tokens":[{"end":93,"kind":"keyword","start":0,"text":"let"}]}
            let arg_list = make.arg_list(Some(make.expr_closure(None, closure_body).into()));
            let cond = if parenthesize { make.expr_paren(cond).into() } else { cond };
            let mcall = make.expr_method_call(cond, make.name_ref("then"), arg_list);