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: http://www.artima.com/pins1ed/packages-and-imports.html#13.2

Or, for the full specification: http://scala-lang.org/files/archive/spec/2.12/04-basic-declarations-and-definitions.html#import-clauses

Harald

I see this got answered at https://stackoverflow.com/questions/46123602/build-sbt-imports-for-docker-commands