Use this method to append one PDF to the end of another one.
Individual pages from one PDF can be drawn into another using
the AddImageDoc method.
If you are inserting a number of pages it is much faster to use
the Append method than to draw pages individually. It also has the
advantage of maintaining other information such as bookmarks.
If you are inserting pages that contain form fields, you may want to call
to avoid sharing fields across pages.
The Refactor setting
determines whether new/modified redundant objects are eliminated.
setting determines whether objects in the destination document are
validated before this operation is performed. Unless the document
and the pages are big in terms of memory use and have many common
objects, it is faster to disable refactor and preflight for adding
the pages and enable them for saving the document. You can use
SetInfo to change these settings.