getWave method
Implementation
Path getWave(Size size) {
Path path = Path();
path.lineTo(0, size.height);
path.quadraticBezierTo(size.width/4, size.height
- 40, size.width/2, size.height-20);
path.quadraticBezierTo(3/4*size.width, size.height,
size.width, size.height-30);
path.lineTo(size.width, 0);
return path;
}