SharedPrefs constructor Null safety

1. unitut_pdf
2. shared
3. SharedPrefs
4. SharedPrefs constructor

SharedPrefs class

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