Overlapping accesses to 'self', but modification requires exclusive access; consider calling MutableCollection.swapAt(_:_:)
Replace 'swap(&self[i], &self[i+j])' with 'self.swapAt(i, i+j)'
Argument of '#selector' refers to instance method 'didPan' that is not exposed to Objective-C
Add '@objc' to expose this instance method to Objective-C
