NavigationBarUtils constructor Null safety

1. baguette
2. NavigationBarUtils
3. NavigationBarUtils
4. NavigationBarUtils constructor

NavigationBarUtils class

1. Constructors
2. NavigationBarUtils
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. createNavigationBar