When I run _"mypy --disallow-any unannotated [foo.py](https://gist.github.com/diamond-lizard/033afc80c97b7cb84913176a259f2b37)",_ mypy tells me that _"[foo.py](https://gist.github.com/diamond-lizard/033afc80c97b7cb84913176a259f2b37):6: error: Function is missing a return type annotation"_. [Here](https://gist.github.com/diamond-lizard/1bb89d6d80b387e1cfc452aa797f3814) is the output of running _"mypy -v --disallow-any unannotated [foo.py](https://gist.github.com/diamond-lizard/033afc80c97b7cb84913176a259f2b37)"_ I'm not sure if this is a bug or if there's some special way I'm supposed to annotate the line mypy is complaining about.