{"ast_node_type":"variable","tokens":[{"end":56,"kind":"keyword","start":0,"text":"let"}]}
    let text = snap.analysis.file_text(frange.file_id)?;
    let frange = try_default!(from_proto::file_range(&snap, &params.text_document, params.range)?);
    let line_index = snap.file_line_index(frange.file_id)?;