Please browse the files in the following package.
growing up-3.pptx.zip (1.4 MB)
When I run the following code:
Presentation presentation = new Presentation(filePath);
int size =((AutoShape)presentation.getSlides().get_Item(0).getShapes().get_Item(1)).getLineFormat().getEffective().getFillFormat().getGradientFormat().getGradientStops().size();
It return 0. I think it should not return an empty array.