toJson method
Implementation
Map<String, dynamic> toJson() {
final height = this.height;
final width = this.width;
final x = this.x;
final y = this.y;
return {
if (height != null) 'height': height,
if (width != null) 'width': width,
if (x != null) 'x': x,
if (y != null) 'y': y,
};
}