{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
                    let ok = self.at(cause, param_env).eq(DefineOpaqueTypes::Yes, v1, v2)?;
                (GenericArgKind::Const(v1), GenericArgKind::Const(v2)) => {
                    obligations.extend(ok.into_obligations());