Forgetting about sub documents, a docx
is made up of a number of sections,
each with their own section properties
(which define page dimensions, margins
So it is natural to think of a document
in terms of sections. But since in Open XML,
all sectPr elements - except the
document level one - are hidden in
paragraphs, our JAXB object model doesn't
expose this structure.
This class does that.
If you have added/deleted sections from your WordprocessingMLPackage,
you'll need to call this method in order for the changes to be
reflected in the DocumentModel.
ppr.getSectPr(), previousHF, rels, evenAndOddHeaders);