The testing code is not working. I made some improvements some time ago but didn't touch again. Maybe we should take this code out of here, then we can think about using some automatic testing after each commit to guarantee things keep working well easily.
https://github.com/PyTTAmaster/PyTTa/blob/f8df054cee04d35668dfc7c70bfd091411e88df0/tests/test_pyttasave.py#L1-L337