invalid_deprecated_mixin_annotation
The annotation '@Deprecated.mixin' can only be applied to classes.
Description
#The analyzer produces this diagnostic when anything other than a mixin class is annotated with Deprecated.mixin.
Example
#The following code produces this diagnostic because the annotation is on a non-mixin class:
dart
@Deprecated.mixin()
class C {}
Common fixes
#Remove the annotation:
dart
class C {}