unusedPrivateDeclarations Deleting private funcs in extensions

[Megatron1000]

Say you've got this

class MyClass {
   func doSomething() {
      doTheThing()
   }
}

extension MyClass {
   private func doTheThing() {
   }
}

doTheThing will be deleted for being unused. I guess it's just checking if it's used within the extension itself.

[calda]

When I test the unusedPrivateDeclarations rule with this sample code, the private func doTheThing() is not removed (the rule correctly notices that the doTheThing method is not unused).