Argyris Zymnis

This ended up being a false alarm. However, there is still an issue with NPEs not being the most useful error message. I will send a pull request to add...

Addressed by #40

Ah seems like this is what [scio](https://github.com/spotify/scio) is doing, albeit using a completely different package. At least they are using algebird under the hood for aggregations. Also they explicitly give...