protected void extractAnnotations(final PDDocument doc, final StringWriter writer) {
        for (final PDPage page : doc.getPages()) {
            try {
                for (final PDAnnotation annotation : page.getAnnotations()) {
                    if (annotation instanceof final PDAnnotationFileAttachment annotationFileAttachment) {
                        final PDFileSpecification fileSpec = annotationFileAttachment.getFile();

                if (methodDesc != null) {
                    final Method method = methodDesc.getMethod();
                    final PreDestroy postConstruct = method.getAnnotation(PreDestroy.class);
                    if (postConstruct != null) {
                        MethodUtil.invoke(method, instance);
                    }
                }
            }