{"ast_node_type":"function","tokens":[{"end":98,"kind":"keyword","start":0,"text":"fn"}]}
    fn deduce_future_output_from_obligations(&self, body_def_id: LocalDefId) -> Option<Ty<'tcx>> {
    #[instrument(skip(self), level = "debug", ret)]
        let ret_coercion = self.ret_coercion.as_ref().unwrap_or_else(|| {