CountryUtils constructor Null safety

1. baguette
2. CountryUtils
3. CountryUtils
4. CountryUtils constructor

CountryUtils class

1. Constructors
2. CountryUtils
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. getCountries
13. getCountry
14. showCountry