Build.sbt imports for docker commands

I have a build.sbt file but I am not able to figure out the role of this import import docker.{addDockerPackage}

Is this an open source import? I am not able to find info about it. Further down in the script it calls a method addDockerPackage()

I wonder if the method is in that package? Or all this is some proprietary stuff? If it is a standard import, where do I read about it?

Scala imports are described e.g. here:

Or, for the full specification:


I see this got answered at