{"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
    let ret_type = ctx.find_node_at_offset::<ast::RetType>()?;
pub(crate) fn unwrap_return_type(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
    let parent = ret_type.syntax().parent()?;