@SubtypeOf(value={})
@Retention(value=RUNTIME)
@DefaultInUncheckedCodeFor(value=RECEIVER)
@Target(value={TYPE_USE,TYPE_PARAMETER})
public @interface GuardedByUnknown
@GuardedByUnknown is the top of the GuardedBy qualifier hierarchy. Any value can be assigned into a variable of type @GuardedByUnknown.