invalid_deprecated_extend_annotation
The annotation '@Deprecated.extend' can only be applied to extendable classes.
Description
#The analyzer produces this diagnostic when anything other than an
extendable class is annotated with
Deprecated.extend. An extendable class is a
class not declared with the interface, final, or sealed keywords,
and with at least one public generative constructor.
Example
#The following code produces this diagnostic because the annotation is on a sealed class:
dart
@Deprecated.extend()
sealed class C {}Common fixes
#Remove the annotation:
dart
sealed class C {}