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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def siphashx24(message, key=b'', encoder=nacl.encoding.HexEncoder):
 """ Computes a keyed MAC of ``message`` using the 128 bit variant of the siphash-2-4 construction. :param message: The message to hash. :type message: bytes :param key: the message authentication key for the siphash MAC construct :type key: bytes(:const:`SIPHASHX_KEYBYTES`) :param encoder: A class that is able to encode the hashed message. :returns: The hashed message. :rtype: bytes(:const:`SIPHASHX_BYTES`) .. versionadded:: 1.2 """

    digest = _sip_hashx(message, key)
    return encoder.encode(digest)