// Need references to these parts to create a slide
// Please note that these parts *already exist* - they are
// created by createPackage() above. See that method
// for instruction on how to create and add a part.
MainPresentationPart pp = (MainPresentationPart)presentationMLPackage.getParts().getParts().get(
new PartName("/ppt/presentation.xml"));
SlideLayoutPart layoutPart = (SlideLayoutPart)presentationMLPackage.getParts().getParts().get(
new PartName("/ppt/slideLayouts/slideLayout1.xml"));
// OK, now we can create a slide