XYCenterGravity constructor Null safety

1. cloudinary_url_gen
2. gravity
3. XYCenterGravity
4. XYCenterGravity constructor

XYCenterGravity class

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