toMap method Null safety

Implementation

@override
Map<String, Object?> toMap() {
  return Map.from(super.toMap())
    ..addAll({
      'coordinates': this.coordinates.map((coord) => coord.toMap()).toList(),
      'indexs': this.indexs.map((index) => index).toList(),
      'width': this.width,
      'colors':
          this.colors?.map((color) => color.value.toRadixString(16)).toList(),
      'textures': this.textures,
      'dottedLine': this.dottedLine,
      'lineDashType': this.lineDashType?.index,
      'lineCapType': this.lineCapType?.index,
      'lineJoinType': this.lineJoinType?.index,
      'lineDirectionCross180': this.lineDirectionCross180?.index,
      'isThined': this.isThined,
      'clickable': this.clickable,
      'isKeepScale': this.isKeepScale,
      'isFocus': this.isFocus,
    });
}