Regression testing is used to check the correctness of evolving software. With the adoption of Agile development methodology, the number of tests and software revisions has dramatically increased, and hence has the cost of regression testing. Researchers proposed regression test selection (RTS) techniques that optimize regression testing by skipping tests that are not impacted by recent program changes. Ekstazi is one such state-of-the art technique; Ekstazi is implemented for the Java programming language and has been adopted by several companies and open-source projects.