docs: def replace_values(in_m, out_m, map_from=(), map_to=()):
      '''
      Make a copy of a model with one value replaced with another
      '''
      for link in in_m.match():
          new_link = list(link)
          if map_from:
              if link[ORIGIN] in map_from: new_link[ORIGIN] = map_to[map_from.index(link[ORIGIN])]
          new_link[ATTRIBUTES] = link[ATTRIBUTES].copy()
          out_m.add(*new_link)
      return