virtual top-level constant
Annotation which no longer has any effect.
Used to annotate a field that is allowed to be overridden in Strong Mode.
Deprecated: This annotation is deprecated and will be
removed in a future release of package:meta.
In Dart 2 and later, overriding fields is allowed by default,
so this annotation no longer has any meaning.
All uses of the annotation should be removed.
Implementation
@Deprecated('No longer has meaning')
const Object virtual = _Virtual();