Codemod is a tool/library to assist you with large-scale codebase refactors that can be partially automated but still require human oversight and occasional intervention. Codemod was developed at Facebook and released as open source.
This suggestion intersects a bit with #64. I think it would make the codebase more readable and extensible if we moved tests out of docstrings and into a separate tests.py module. This would make it easier to write more involved tests such as the one we need to reproduce the bug in #33.
