toOptionsJSON method
Implementation
@override
void toOptionsJSON(StringBuffer buffer) {
  super.toOptionsJSON(buffer);
  if (description != null) {
    buffer.writeAll(['"description":', jsonEncode(description), ','], '');
  }
  if (enabled != null) {
    buffer.writeAll(['"enabled":', enabled, ','], '');
  }
  if (rangeDescription != null) {
    buffer.writeAll(
        ['"rangeDescription":', jsonEncode(rangeDescription), ','], '');
  }
}