So at the time I was playing around with the Pylama I checked out the repo and run the tests. 80% of them were failing. I did not know why. So I took one of checkers, I guess `pep257` and did a clean run on Win and Linux. There diffrence was that on Win addidional error (see above in code) was present - due to different handling of trailing whitespaces and line endings on those platforms. I have to support projects on different platforms such things happened to me before. After introducing in test case security check for platform and appending this one difference - tests are ok - both on Win and Unix - so I guess it is ok. The returned by test case value was not changed.