This blog post is part of a series about legacy coderetreat<\/a> and legacy code techniques you can apply during your work. Please click to see more sessions<\/a> about legacy code.<\/p>\n This is a code cast in Java.<\/p>\n In the first episode<\/a> we wrote some characterization tests with the purpose to create a basic safety net. Now we continue to refactor the code, starting from there. We already have some tests running and we want to have methods that do only one thing; we want to apply the Single Responsibility Principle. A really good tool that can help is using pure functions. We extract functions, make them static and then make sure the function does not have any side effects. These functions help me clean the code and help me start structurig the code according to clear responsibilities. At a later time we will extract all these functions that have similar responsibilities to a new class.<\/p>\n Read here<\/a> more about this concept in my blog post.<\/p>\nCode Cast<\/h3>\n