title: Is calling methods in parent class a bad idea?
body: <p>In real world project, we had a pretty long PHP class, and during refactoring it was broken into 2 smaller classes, ClassA and ClassB, where ClassA extends ClassB (just an example names). There were some issues with legacy code, so we had to do that way.</p>
  
  <p>In ClassB we call some methods from ClassA (they're not overriden, I mean, methods doesn't exists in ClassB). Is that a bad idea in OOP?</p>
  
  <p>Edit: obviosly, in the rest of code we always initiate only ClassA. But wondering is calling parent class from the child a big "NO" in OOP terms?</p>