duplicates:

• SR-2817 selector mismatch with obj-c delegates + extensions

Issue Description:

With the change described in SE-0005, some obvious words in Objective-C method names are now omitted when translating to Swift 3. However, in the case below, the method name translation does not work correctly making the obvious words NOT get omitted.

import UIKit

class SuperClass: NSObject, UICollectionViewDelegate {}
class SubClass: SuperClass {
  func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
    print("NEW TRANSLATION")
  }

  func collectionView(_ collectionView: UICollectionView, willDisplayCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: IndexPath) {
    print("OLD TRANSLATION")
  } 
}

SuperClass is declared to be conformed to UICollectionViewDelegate protocol but does not implement any method from the protocol. SubClass is inherited from SuperClass and actually implements an optional method defined in UICollectionViewDelegate.
Now assign an instance of SubClass as the delegate of a UICollectionView, the string "OLD TRANSLATION" will be printed when the delegate method is called while users would expect "NEW TRANSLATION" instead. That means Swift 3 method name translation rule does not work correctly in this case.