import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
class X extends A {
@NotNull
@Override
String foo(int n, @Nullable String s, @NotNull Object o) {
return "";
}
}
class Y extends A {
@Nullable
@Override
String foo(int n, @Nullable String s, @NotNull Object o) {
return "";
}
}
class Z extends A {
@Nullable
@Override
String foo(int n, @Nullable String s, @NotNull Object o) {
return "";
}
}