def oldNullability = hasNullableAnnotation(oldField)
            def newNullability = hasNullableAnnotation(newField)

            if (Modifier.isFinal(oldField.modifiers) && Modifier.isFinal(newField.modifiers)) {
                if (!oldNullability && newNullability) {
                    errors << "From non-nullable to nullable breaking change"

            }
            return acceptOrReject(member, changes, Violation.error(member, "Breaking Kotlin modifier change"))
        }

        return null
    }

    private static String modifierChangeDetail(String modifier, boolean added) {
        return "$modifier modifier was ${added ? "added" : "removed"}"
    }

        result.addAll(c.declaredMethods.findAll { isPublicApi(it) })

        collect(result, c.superclass)
    }

    private boolean isPublicApi(CtMethod method) {
        return Modifier.isPublic(method.modifiers) || Modifier.isProtected(method.modifiers)
    }

    private List<String> filterChangesToReport(CtClass c, Set<CtMethod> methods) {
        return methods.findAll { isFirstPublicClassInHierarchy(it, c) }*.longName.sort()
    }

    IncubatingInternalInterfaceAddedRule(Map<String, Object> params) {
        super(params)
    }

    protected boolean changed(JApiCompatibility member) {
        return member.getChangeStatus() == JApiChangeStatus.MODIFIED
    }

    protected Violation checkSuperClassChanges(JApiClass c, CtClass oldClass, CtClass newClass) {
        Map<String, CtClass> oldInterfaces = collectImplementedInterfaces(oldClass)

        incubatingInterface = instanceScopedPool.get(IncubatingInterface.name)
        stablePublicInterface = instanceScopedPool.get(StablePublicInterface.name)

        apiClass.changeStatus >> JApiChangeStatus.MODIFIED
        apiClass.oldClass >> Optional.of(oldBase)
        apiClass.newClass >> Optional.of(newBase)

        internalInterface.name = replaceAsInternal(internalInterface.name)