AlbumFromModel constructor Null safety

1. next_photo
2. features
3. AlbumFromModel
4. AlbumFromModel constructor

AlbumFromModel class

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