copyWith method Null safety
- {BorderSide? side,
 - BorderRadiusGeometry? borderRadius}
 
override
    Returns a copy of this OutlinedBorder that draws its outline with the
specified side, if side is non-null.
Implementation
@override
ContinuousRectangleBorder copyWith({ BorderSide? side, BorderRadiusGeometry? borderRadius }) {
  return ContinuousRectangleBorder(
    side: side ?? this.side,
    borderRadius: borderRadius ?? this.borderRadius,
  );
}