Also are you sure about your assertion there? In *this* implementation at least, it does not seems correct.
Reading this code (and especially the fact it may generate None values), it looks to me that the intention was that this generator always generates as many values as was given in the content parameter (not sure why nor if it is needed somewhere, instead of of not yielding None values, but that's another fine-tune-API debate).
- fix doc
Oops, indeed. I updated the docstring to mention that for now it returns exactly as many items, but that it may change in the future.
Ugh, I don't know why I wrote this. And that's not even a generator.