How to animated border of container in flutter - flutter

Question

I want to draw animated border around the square container with infinity loop (never stop) like this photo , I'm trying animated container bust not help me
so can anyone tell me how to implement line animation
Edit **
I'm using this code to draw the square but I can't make it build with animation
class RadialPainter extends CustomPainter {
final double progressRemoval;
final Color color;
final StrokeCap strokeCap;
final PaintingStyle paintingStyle;
final double strokeWidth;
final double progress;
RadialPainter(
{this.progressRemoval,
this.color,
this.strokeWidth,
this.strokeCap,
this.paintingStyle,
this.progress});
#override
void paint(Canvas canvas, Size size) {
Paint paint = Paint()
..strokeWidth = strokeWidth
..color = color
..style = paintingStyle
..strokeCap = strokeCap;
var progressRemoval = 0.50;
var path = Path();
//LINEA SUPERIOR DEL CUADRADO
path.moveTo((size.width * 0.30), 0);
path.quadraticBezierTo((size.width * 0.30), 0, size.width, 0);
//LATERAL DERECHO
path.moveTo(size.width, 0);
path.quadraticBezierTo(size.width, 0, size.width, size.height);
//LINEA INFERIOR DEL CUADRADO
path.moveTo(size.width, size.height);
path.quadraticBezierTo(size.width, size.height, 0, size.height);
//LINEA IZQUIERDA
path.moveTo(0, size.height);
path.quadraticBezierTo(0, (size.height * 0.75), 0, ((size.height * 0.75)));
canvas.drawPath(path, paint);
}
#override
bool shouldRepaint(RadialPainter oldDelegate) {
return oldDelegate.progress != progress;
}
}
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