public enum UpdatingStrategy
The updating strategy when an intermediate progressive image is generated and about to be set to the hosting view.
default: Use the progressive image as it is. It is the standard behavior when handling the progressive image.
keepCurrent: Discard this progressive image and keep the current displayed one.
replace: Replace the image to a new one. If the progressive loading is initialized by a view extension in Kingfisher, the replacing image will be used to update the view.