toJson method
Implementation
@override
Map<String, dynamic> toJson() => {
...super.toJson(),
if (strokeColor != null) 'strokeColor': strokeColor,
if (strokeSize != null) 'strokeSize': strokeSize,
if (fillColor != null) 'fillColor': fillColor,
if (scaleX != null) 'scaleX': scaleX,
if (scaleX != null) 'scaleY': scaleY,
};