ArcPainter constructor
ArcPainter()
Implementation
ArcPainter(this.radius, this.strokeWidth, this.arcStart, this.arcEnd,
this.color, this.notifier)
: super(repaint: notifier) {
circlePaint
..color = color
..strokeWidth = strokeWidth
..style = PaintingStyle.stroke
..strokeCap = StrokeCap.round;
}