toJson method 
    
      
dynamic
toJson(
[ - bool addGeometry = true
]) 
    
    
  Implementation
  dynamic toJson([bool addGeometry = true]) {
  final json = <String, dynamic>{};
  void addIfPresent(String fieldName, dynamic value) {
    if (value != null) {
      json[fieldName] = value;
    }
  }
  addIfPresent('circleRadius', circleRadius);
  addIfPresent('circleColor', circleColor);
  addIfPresent('circleBlur', circleBlur);
  addIfPresent('circleOpacity', circleOpacity);
  addIfPresent('circleStrokeWidth', circleStrokeWidth);
  addIfPresent('circleStrokeColor', circleStrokeColor);
  addIfPresent('circleStrokeOpacity', circleStrokeOpacity);
  if (addGeometry) {
    addIfPresent('geometry', geometry?.toJson());
  }
  addIfPresent('draggable', draggable);
  return json;
}