PredominantGradientBackground constructor Null safety

1. cloudinary_url_gen
2. predominant_background
3. PredominantGradientBackground
4. PredominantGradientBackground constructor

PredominantGradientBackground class

1. Constructors
2. PredominantGradientBackground
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. contrast
8. getValues
9. gradientColors
10. gradientDirection
11. noSuchMethod
12. palette
13. toString
14. Operators
15. operator ==