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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 _const_compare_digest_backport(a, b):
 """ Compare two digests of equal length in constant time. The digests must be of type str/bytes. Returns True if the digests match, and False otherwise. """

    result = abs(len(a) - len(b))
    for l, r in zip(bytearray(a), bytearray(b)):
        result |= l ^ r
    return result == 0