Before submitting a pull request, please do the following steps:

1. Read instructions for contributors [here](https://tech.yandex.com/catboost/doc/dg/concepts/development-and-contributions-docpage/).
2. Run `ya make` in catboost folder to make sure the code builds.
3. Add tests that test your change.
4. Run tests using `ya make -t -A` command.
5. If you haven't already, complete the CLA.