Yep, just copy-paste a bit of REPL history for a docstring, then use `doctest` to make sure it holds. Pretty soon you'll have ~100% test coverage. Minus the e

Yep, just copy-paste a bit of REPL history for a docstring, then use `doctest` to make sure it holds. Pretty soon you'll have ~100% test coverage. Minus the error paths you didn't test in REPL.