IBANValidator constructor Null safety

1. baguette
2. IBANValidator
3. IBANValidator
4. IBANValidator constructor

IBANValidator class

1. Constructors
2. IBANValidator
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. validate
10. Operators
11. operator ==