@Override
    public ArmeriaResteasyClientBuilder connectionCheckoutTimeout(long timeout, TimeUnit unit) {
        delegate.connectionCheckoutTimeout(timeout, unit);
        return this;
    }
{@link ArmeriaJaxrsClientEngine} will always be set as an {@link ClientHttpEngine}.
@throws UnsupportedOperationException always
resteasy/src/main/java/com/linecorp/armeria/client/resteasy/ArmeriaResteasyClientBuilder.java