(see L<http://libvirt.org/uri.html>). If this is not set then
we connect to the default libvirt URI (or one set through an
environment variable, see the libvirt documentation for full
-details). If you are using the C API directly then it is more
-flexible to create the libvirt connection object yourself, get
-the domain object, and call C<guestfs_add_libvirt_dom>.
+details).
The other optional parameters are passed directly through to
C<guestfs_add_drive_opts>.");