code: def add_prefix(multicodec, bytes_):
      
      prefix = get_prefix(multicodec)
      return b''.join([prefix, bytes_])
docs: Adds multicodec prefix to the given bytes input
  
      :param str multicodec: multicodec to use for prefixing
      :param bytes bytes_: data to prefix
      :return: prefixed byte data
      :rtype: bytes