paddingOnly method
return custom padding from each side
Implementation
Padding paddingOnly({
  double top = 0.0,
  double left = 0.0,
  double bottom = 0.0,
  double right = 0.0,
}) {
  return Padding(
    padding: EdgeInsets.fromLTRB(left, top, right, bottom),
    child: this,
  );
}