Skip back a number of revisions when reading an incrementally
saved PDF document.
PDF documents can be incrementally updated so that changes are
appended to the document rather than overwriting the original. This
means that it is possible to revert back to a previous version of
the document. Setting this value allows you to skip back a
specified number of revisions.
IndirectObject.Revision property and the
ObjectSoup.Revisions property for determining the number of
revisions a document contains and the content which is associated
with each revision.