{"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":")"}]}
            ) if a_def_id == b_def_id => {
                &ty::Alias(ty::Opaque, ty::AliasTy { def_id: b_def_id, .. }),
                super_combine_tys(infcx, self, a, b)?;