BottomNavigationBarItem constructor
Creates an item that is used with BottomNavigationBar.items.
The argument icon should not be null and the argument label should not be null when used in a Material Design's BottomNavigationBar.
Implementation
const BottomNavigationBarItem({
this.key,
required this.icon,
this.label,
Widget? activeIcon,
this.backgroundColor,
this.tooltip,
}) : activeIcon = activeIcon ?? icon;