api/jar/src/main/java/javax/slee/usage/UsageNotification.java
private void writeObject(ObjectOutputStream out) throws IOException {
        VendorExtensionUtils.writeObject(out, vendorDataSerializationEnabled ? vendorData : null);
    }
private void writeObject(ObjectOutputStream out) throws IOException {
        VendorExtensionUtils.writeObject(out, vendorDataSerializationEnabled ? vendorData : null);
    }
special handling of serialization