{"ast_node_type":"function","tokens":[{"end":89,"kind":"keyword","start":0,"text":"pub(crate)"}]}
pub(crate) fn add_return_type(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
// ```
    let (fn_type, tail_expr, builder_edit_pos) = extract_tail(ctx)?;