protected abstract val nullableAnnotationName: String

    @Test
    fun `from non-null returning to null returning is breaking`() {

        checkNotBinaryCompatibleJava(
            v1 = """
                public class Source {
                    public String nonFinalField = "some";
                    public final String finalField = "some";

    private val nullUnmarkedAnnotationName = "org.jspecify.annotations.NullUnmarked"

    @Test
    fun `from non-null returning to null-unmarked returning is breaking`() {

        checkNotBinaryCompatibleJava(
            v1 = """
                public class Source {
                    public String foo() { return "bar"; }
                    public String[] baz() { return new String[] {"some"}; }
                }