Implement a method to change the order of shapes within a slide or group. It should be possible to move them relative to the current position in the shape tree and also absolute to the beginning or end. see also: https://stackoverflow.com/questions/39943923/apache-poi-change-shape-order-in-pptx https://stackoverflow.com/questions/53383742/how-to-change-zorder-in-apache-poi-for-pptx-shapes