PopupUtils constructor Null safety

1. baguette
2. PopupUtils
3. PopupUtils
4. PopupUtils constructor

PopupUtils class

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