RepaintBoundary.wrap constructor
Wraps the given child in a RepaintBoundary.
The key for the RepaintBoundary is derived either from the child's key
(if the child has a non-null key) or from the given childIndex
.
Implementation
RepaintBoundary.wrap(Widget child, int childIndex)
: super(key: ValueKey<Object>(child.key ?? childIndex), child: child);