distfiles from launchpad.net

[John Hein]

I am looking at updating a port that now lives on launchpad.net, but
I don't see anything for launchpad.net in bsd.sites.mk

Does anyone know anything about how launchpad.net and its mirrors (if
any) support downloads?  Or can suggest a way to support that site
in bsd.sites.mk.

Here are some examples of distfile URLs...
https://launchpad.net/bzr/1.11/1.11/+download/bzr-1.11.tar.gz
http://launchpad.net/bzr/2.1/2.1.0b1/+download/bzr-2.1.0b1.tar.gz
http://launchpad.net/vm/trunk/8.1.0-beta/+download/vm-8.1.0-beta.tgz