#branch todo
- fix hvAsync
- fix hvArray
- hvBind test
- hv scope

- reconsider hvEval
- add hvAsync
    - write tests!
- add hvNormalize/hvGet (hv<T> | T) => T
- hvIn / hvOut
- catch
- hv helper
- better clean-up system
- do not update if new value is equal to old one
- async duplex