code: func provisionerMapKey(k string, v dag.Vertex) string {
  	pathPrefix := ""
  	if sp, ok := v.(GraphNodeSubPath); ok {
  		pathPrefix = sp.Path().String() + "."
  	}
  
  	return pathPrefix + k
  }
docs: // provisionerMapKey is a helper that gives us the key to use for the
  // maps returned by things such as provisionerVertexMap.