The little things we do... Someone suggested that we should not modify a method. We should instead rewrite it if we want a change in behavior. If you think it is preposterous, read on. The central idea is that we should arrive for good test coverage. However, when we modify an existing method, we will be more conscientious of edge cases of we rewrite the whole method from scratch. Moreover, it isn't as crazy as we think at first because if we talk about Dependency Injection and testing, we should write short methods that don't do too much™ anyway.