docs: def get_mg_path(model_run, model_num):
      """
      model_run = integer, e.g. 15, 16, corresponding to the v-number
      model_num = integer, e.g 939, for the model number in that run
      """
      fsdb.switch_base("minigo-pub/v{:d}-19x19".format(model_run))
      model = fsdb.get_model(model_num)
      return os.path.join(fsdb.models_dir(), model)