Gremllm

  from gremllm import Gremllm

  # Be sure to tell your gremllm what sort of thing it is
  counter = Gremllm('counter')
  counter.value = 5
  counter.increment()
  print(counter.value)  # 6?
  print(counter.to_roman_numerals()) # VI?

I love this!

Awesome, now I don't have to write mocks for testing!