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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 get_bytes(s):
 """Returns the byte representation of a hex- or byte-string."""

    if isinstance(s, bytes):
        b = s
    elif isinstance(s, str):
        b = bytes.fromhex(s)
    else:
        raise TypeError("s must be either 'bytes' or 'str'!")

    return b