code: func namePartFromDimensions(m stringmapflag.Value) string {
  	a := mapToArray(m)
  	pairs := make([]string, 0, len(a))
  	for i := 0; i < len(a); i++ {
  		pairs = append(pairs, fmt.Sprintf("%s=%s", a[i].Key, a[i].Value))
  	}
  	return strings.Join(pairs, "_")
  }
docs: // namePartFromDimensions creates a string from a map of dimensions that can
  // be used as part of the task name.  The dimensions are first sorted as
  // described in mapToArray().