encode method Null safety

Implementation

Object encode() {
  final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
  pigeonMap['enabled'] = enabled;
  pigeonMap['position'] = position?.index;
  pigeonMap['marginLeft'] = marginLeft;
  pigeonMap['marginTop'] = marginTop;
  pigeonMap['marginRight'] = marginRight;
  pigeonMap['marginBottom'] = marginBottom;
  pigeonMap['textColor'] = textColor;
  pigeonMap['primaryColor'] = primaryColor;
  pigeonMap['secondaryColor'] = secondaryColor;
  pigeonMap['borderWidth'] = borderWidth;
  pigeonMap['height'] = height;
  pigeonMap['textBarMargin'] = textBarMargin;
  pigeonMap['textBorderWidth'] = textBorderWidth;
  pigeonMap['textSize'] = textSize;
  pigeonMap['isMetricUnits'] = isMetricUnits;
  pigeonMap['refreshInterval'] = refreshInterval;
  pigeonMap['showTextBorder'] = showTextBorder;
  pigeonMap['ratio'] = ratio;
  pigeonMap['useContinuousRendering'] = useContinuousRendering;
  return pigeonMap;
}