{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"if"}]}
        if let Some(closure) = ctx.find_node_at_offset::<ast::ClosureExpr>() {
    let (fn_type, tail_expr, return_type_range, action) =
            let rpipe = closure.param_list()?.syntax().last_token()?;