static Function<? super RpcService, SimpleDecoratingRpcService> newDecorator(
            Iterable<TransientServiceOption> transientServiceOptions) {
        requireNonNull(transientServiceOptions, "transientServiceOptions");
        return delegate -> new WrappingTransientRpcService(delegate,
                                                           Sets.immutableEnumSet(transientServiceOptions));
    }
Returns a new {@link RpcService} decorator which makes the specified {@link RpcService} as
{@link TransientService}.
core/src/main/java/com/linecorp/armeria/server/TransientRpcService.java