Use this method to determine whether an object is chainable.
Some objects can be chained. A chunk of text may be chained from
page to page on the output PDF. Similarly, a web page may be
chained from page to page.
This method allows you to determine whether the object you have
added is chainable or whether it is at the end of the chain.
Only text, PostScript images and web pages can be chainable. So
your ID should have been obtained from a previous call to one of
the AddImage family of calls or from