title: ProGuard - leave only one class in package
body: <p>I have package with 10 classes, one of them "ClassX" I need keep (because if I change it name then all old serialized object will not work) but if I add this one class ("ClassX") to exceptions then that 9 classes are still in this same package, but I want to move all classes to one package except only this one class ("ClassX").</p>
  
  <p>Is that possible?</p>