docs: def make_data_script( data, blockchain='bitcoin', **blockchain_opts):
      """
      High-level API call (meant to be blockchain agnostic)
      Make a data-bearing transaction output.
      Data must be a hex string
      Returns a hex string.
      """
      if blockchain == 'bitcoin':
          return btc_make_data_script(data, **blockchain_opts)
      else:
          raise ValueError("Unknown blockchain '{}'".format(blockchain))