{"ast_node_type":"other","tokens":[{"end":71,"kind":"keyword","start":0,"text":"with_metavar_spans(|mspans|"}]}
            with_metavar_spans(|mspans| mspans.insert(ident.span, sp));
            tscx.marker.mark_span(&mut sp);
            let kind = token::NtLifetime(*ident, *is_raw);