line collections

I thought I would implement draw_line_collection() for Cairo and looked for
an example script I could use for testing. Yet after adding a
'print "line collection"' statement to backend_bases.draw_line_collection()
and running backend_driver.py I did not see any examples using line collections.
Does this mean that line collections are not useful, or just that there is
no example script (called by backend_driver.py) which uses line collections?

Also, is it worthwhile implementing these collections routines or are they
effectively deprecated and about to be superseded by new path based drawing
routines?

Steve