Merge PPTM Files in Java

Presentation destinationPresentation = new Presentation("presentation1.pptm");
try {
    Presentation sourcePresentation = new Presentation("presentation2.pptm");
    try {
        for (ISlide slide : sourcePresentation.getSlides()) {
            destinationPresentation.getSlides().addClone(slide);
        }
    } finally {
        sourcePresentation.dispose();
    }

    destinationPresentation.save("merged-presentation.pptm", SaveFormat.Pptm);
} finally {
    destinationPresentation.dispose();
}