Examples or documentation on UpdateServiceAsync

I'm looking for examples or documentation on how to update service using this SDK. I have a successfully connected client, can list containers and services, and kill containers. But when I'm trying to use client.Swarm.UpdateServiceAsync I just can't seem to make it work.

My goal (for now) is to toggle a service between 0 or 1 replicas with a single button press from a custom UI.

I've tried copying the spec from the original service retrieved with the ListServicesAsync method.
```
private async Task Toggle(SwarmService service)
{
var parameters = new ServiceUpdateParameters();
parameters.Service = service.Spec;
parameters.Service.Mode.Replicated.Replicas = (ulong?)(service.Spec.Mode.Replicated.Replicas.GetValueOrDefault(0) == 0 ? 1 : 0);

await client.Swarm.UpdateServiceAsync(service.ID, parameters);
}
```
which yields the error
```
Docker.DotNet.DockerApiException: 'Docker API responded with status code=InternalServerError, response={"message":"rpc error: code = Unknown desc = update out of sequence"}'
```

I've also tried with making a blank spec, containing only the change that I want to make
```
private async Task Toggle(SwarmService service)
{
var parameters = new ServiceUpdateParameters();
parameters.Service = new ServiceSpec();
parameters.Service.Mode = new ServiceMode();
parameters.Service.Mode.Replicated = new ReplicatedService();
parameters.Service.Mode.Replicated.Replicas = (ulong?)(service.Spec.Mode.Replicated.Replicas.GetValueOrDefault(0) == 0 ? 1 : 0);

await client.Swarm.UpdateServiceAsync(service.ID, parameters);
}
```
which yields the errorr
```
Docker.DotNet.DockerApiException: 'Docker API responded with status code=BadRequest, response={"message":"mismatched Runtime and *Spec fields"}'
```
I've also tried various other mixes, but all led to one of the errors mentioned above.