eState.reason2 = r;
        if (teeState.canceled1) {
            @readableStreamCancel(stream, [teeState.reason1, teeState.reason2]).@then(
                teeState.cancelPromiseCapability.@resolve,
                teeState.cancelPromiseCapability.@reject);
        }
        return teeState.cancelPromiseCapability.@promise;
    }
})