shadow method
Add box shadow
Implementation
BoxDecoration shadow({
Color color = Colors.black26,
double blurRadius = 10,
Offset offset = const Offset(0, 4),
double spread = 0,
}) =>
copyWith(
boxShadow: [
...(boxShadow ?? []),
BoxShadow(
color: color,
blurRadius: blurRadius,
offset: offset,
spreadRadius: spread,
),
],
);