{"ast_node_type":"variable","tokens":[{"end":15,"kind":"keyword","start":0,"text":"let"}]}
    let do_nl =
        |pos: fn(_) -> Position, token: &SyntaxToken| (pos(token.clone()), PrettifyWsKind::Space);
        |pos: fn(_) -> Position, token: &SyntaxToken| (pos(token.clone()), PrettifyWsKind::Newline);