Confused about simpleDataFetch example - no hint of actual implementation

[cambiata]

As a XState newbie, I'm a bit confused when finding the simpleDataFetch example -
there is no hint at all about how to actually implement actual (real or mock) data fetching:

• where should the fetch code live? (In the empty services: fetchData method, I guess...)
• how should I notify the machine about a sucessful fetch request? (sending an RECEIVE_DATA event together with the associated data:Data field back to the machine, I guess...)
• how should I notify the machine about a data loading error? (No idea, there is no error type event...)
• how can the Variables type be used? (No idea...)

At least, the simpleDataFetch example should have some commented out implementation example lines to give the user (me!) an idea about how to get some actual data flowing.

Best! / Jonas