ofPath getVertices, possible with an open path like a line?

I’ve already understood I have to use line width > 0 to be able to use getVertices command
but I can’t convert a simple line (two points) to ofPolyline. Is there some way to do that? if not, is this the intended usage of getVertices? only for closed polygons or 3 or more points?
Anyway I’ll try to make some rectangles and use the first two points for now[.]
(http://network-marketing.ning.com/profiles/blogs/giai-ma-giac-mo-tiet-kiem-tien)

Thank you

[há hắng]
(http://network-marketing.ning.com/profiles/blogs/giai-ma-giac-mo-tiet-kiem-tien)