Dapr's virtual actors sounds like a good idea, but besides the API spec[1] is there any better doc to have a look to an example? How are the callbacks used..?

Dapr's virtual actors sounds like a good idea, but besides the API spec[1] is there any better doc to have a look to an example? How are the callbacks used..? I want to give it a try, but really seems that is pre-alpha. [1] https://github.com/dapr/docs/blob/master/reference/api/actors.md https://github.com/dapr/docs/blob/master/reference/api/actor...