SliverOpacity constructor Null safety
Creates a sliver that makes its sliver child partially transparent.
The opacity argument must not be null and must be between 0.0 and 1.0 (inclusive).
Implementation
const SliverOpacity({
super.key,
required this.opacity,
this.alwaysIncludeSemantics = false,
Widget? sliver,
}) : assert(opacity != null && opacity >= 0.0 && opacity <= 1.0),
assert(alwaysIncludeSemantics != null),
super(child: sliver);