{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
            let t = Token::new(TokenKind::Ident(sym::None, false.into()), Span::default());
            // For simplicity, we just add a dummy token to the end of the list.
            ts.push(TokenTree::Token(t, Spacing::Joint));