{"ast_node_type":"variable","tokens":[{"end":23,"kind":"keyword","start":0,"text":"if"}]}
        if let Err(_) =
    fn equate_normalized_input_or_output(&mut self, a: Ty<'tcx>, b: Ty<'tcx>, span: Span) {
            self.eq_types(a, b, Locations::All(span), ConstraintCategory::BoringNoLocation)