longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(self.handleLongGesture(gesture:)))
    uploadDocCollectionView.addGestureRecognizer(longPressGesture)
 @objc func handleLongGesture(gesture: UILongPressGestureRecognizer) {

        switch(gesture.state) {

        case UIGestureRecognizerState.began:
            guard let selectedIndexPath = self.uploadDocCollectionView.indexPathForItem(at: gesture.location(in: self.uploadDocCollectionView)) else {
        break

        }
        uploadDocCollectionView.beginInteractiveMovementForItem(at: selectedIndexPath)
        case UIGestureRecognizerState.changed:
            uploadDocCollectionView.updateInteractiveMovementTargetPosition(gesture.location(in: gesture.view!))
        case UIGestureRecognizerState.ended:
        uploadDocCollectionView.endInteractiveMovement()
        default:
        uploadDocCollectionView.cancelInteractiveMovement()


       }
}

func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
    print("Starting Index: (sourceIndexPath.item)")
    print("Ending Index: (destinationIndexPath.item)")
}