{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
        let last_line_trimmed = last_line.trim_start_matches(is_whitespace);
        let last_line = &within[last_line_start..];
        let last_line_start_pos = frontmatter_opening_end_pos + BytePos(last_line_start as u32);