NavigationRailTheme constructor Null safety

const NavigationRailTheme(
  1. {Key? key,
  2. required NavigationRailThemeData data,
  3. required Widget child}

Creates a navigation rail theme that controls the NavigationRailThemeData properties for a NavigationRail.

The data argument must not be null.


const NavigationRailTheme({
  Key? key,
  required Widget child,
}) : assert(data != null), super(key: key, child: child);