code: func VersionSource(rev, ver, verPre string) Source {
  	return Source{
  		Name:   "version",
  		Format: "hcl",
  		Data:   fmt.Sprintf(`revision = %q version = %q version_prerelease = %q`, rev, ver, verPre),
  	}
  }
docs: // VersionSource creates a config source for the version parameters.
  // This should be merged in the tail since these values are not
  // user configurable.