FlatShadeFilter constructor Null safety

1. Flutter
2. vector_math_geometry
3. FlatShadeFilter
4. FlatShadeFilter constructor

FlatShadeFilter class

1. Constructors
2. FlatShadeFilter
3. Properties
4. generates
5. hashCode
6. inplace
7. requires
8. runtimeType
9. Methods
10. filter
11. noSuchMethod
12. toString
13. Operators
14. operator ==