EmojiLayerOverlay constructor
      const
      EmojiLayerOverlay({ 
    
    
- Key? key,
 - required EmojiLayerData layer,
 - required int index,
 - required Function onUpdate,
 - required IndexChange indexChange,
 
Implementation
const EmojiLayerOverlay(
    {Key? key,
    required this.layer,
    required this.index,
    required this.onUpdate,
    required this.indexChange})
    : super(key: key);