onPaint method
Implementation
@override
void onPaint(PaintingContext context, Offset offset) {
  context.canvas.save();
  final Rect clip = clipRect(
    paintBounds,
    animationFactor,
    isInversed: xAxis!.isInversed,
    isTransposed: isTransposed,
  );
  context.canvas.clipRect(clip);
  paintSegments(context, offset);
  context.canvas.restore();
  paintMarkers(context, offset);
  paintDataLabels(context, offset);
  paintTrendline(context, offset);
}