Cloudsigma provider - config and constraints

Juju provider for CloudSigma.

Provider for CloudSigma (https://www.cloudsigma.com) uses CloudSigma API v2.0 (https://cloudsigma-docs.readthedocs.org/en/2.10/).

Minimal client for communicating with the CloudSigma Web API from Go program was implemented as separate library https://www.github.com/Altoros/gosigma. This library is published under AGPLv3 license.
given this code: https://github.com/Altoros/juju-cloudsigma/pull/1/files#diff-5fce0e10d4a415c83c2dede97c183dfaR37
isn't this actually a short or a long URL? (so it can be 'zrh' but it can also be http://zrh.cloudsigma.com or something along those lines.