how to make container borderline dispear in flutter code example

Example 1: add only bottom border to container flutter

decoration: BoxDecoration(
          border: Border(
            top: BorderSide(width: 16.0, color: Colors.lightBlue.shade600),
            bottom: BorderSide(width: 16.0, color: Colors.lightBlue.shade900),
          ),
          color: Colors.white,
        ),

Example 2: container border flutter

BoxDecoration myBoxDecoration() {
  return BoxDecoration(
    border: Border.all(),
  );
}