{"ast_node_type":"variable","tokens":[{"end":84,"kind":"keyword","start":0,"text":"let"}]}
    let mut block = ast::BlockExpr::cast(l_curly_token.parent_ancestors().nth(1)?)?;
    let l_curly_token = ctx.find_token_syntax_at_offset(T!['{'])?;
    let target = block.syntax().text_range();