{"ast_node_type":"variable","tokens":[{"end":61,"kind":"keyword","start":0,"text":"let"}]}
    let search_range = closure.body()?.syntax().text_range();
    let closure = token.parent_ancestors().take(2).find_map(ast::ClosureExpr::cast)?;
    let ty = &sema.type_of_expr(&closure.into())?.original;