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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 address_checksum(address):
 """ Returns the checksum in bytes for an address in bytes """

    address_bytes = address
    h = blake2b(digest_size=5)
    h.update(address_bytes)
    checksum = bytearray(h.digest())
    checksum.reverse()
    return checksum