Already over 120 people bought [the Rector book](/blog/rector-the-power-of-automated-refactoring-book-released) that we released just a month ago. The continuously growing interest in abstract syntax technology makes me very happy. It leads to more developers **who can write their own custom Rector rules to improve their specific projects**. That leads to more "how-to" questions in the Rector repository. I've decided to answer one of the frequent ones today.
