vPim and Attaching vCard to iCalendar

Is anyone familiar with the vPim gem
(GitHub - sam-github/vpim: vCard and iCalendar support for ruby)?
I’ve been successful creating different iCalendars and vCards. However,
trying to attach a vCard to an event in an iCalendar file. This article
describes exactly why and how I want to do this:
mobicontact.info . I can’t
seem to find or understand any documentation on how this is done with
There are references to this capability in the docs but not very well
explained: File: README — Documentation for vpim (0.695) .

I’m using this in Rails 3.2.8 w/ Ruby 1.9.3

BIG thanks in advance for any help.