LKLabelAction.swift

extension LKLabel {
    open override func action(for layer: CALayer, forKey event: String) -> CAAction? {
        let result = super.action(for: layer, forKey: event)
        if event == keyPath(\CALayer.bounds) && result != nil && UIView.inheritedAnimationDuration > 0 {
            let textDrawingBoundsAction = LKBoundsDidChangeAction(fromBounds: layer.bounds)
            let action = LKCompositeAction(actions:[result!, textDrawingBoundsAction])
            return action
        }
        return result
    }
}