Latest PR - https://github.com/jenkinsci/workflow-cps-plugin/pull/18

In my experience of Groovy the distinction between different ways to getting at things is pretty vague. I understand that a properties, methods, fields, and instances are diffent, but from a usage standpoint, the language seems to be designed to minimize one's awareness of those differences. From an end-user/pipeline-writer perspective, treating the global variables differently than we treat method is more confusing that helpful.

I'll second what bitwiseman is saying, as a Pipeline user, the distinction between different flavors of API reference documentation is not really relevant to me. With the docker variable, for example, there are methods hanging off of that which I think of, and work with, like other "steps".

The docker variable is a different case, and to deal with that properly really requires a separate API: JENKINS-32731.

Actually got merged a while back.