toJson method
Implementation
Map<String, Object?> toJson() {
  var self = this.self;
  var value = this.value;
  final json = <String, Object?>{};
  if (self != null) {
    json[r'self'] = self;
  }
  if (value != null) {
    json[r'value'] = value;
  }
  return json;
}