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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 simple_pairing_rand(self):
 """Simple Pairing Randomizer R. Received and transmitted as EIR type 0x0F. Set to None if not received or not to be transmitted. Raises nfc.ndef.DecodeError if the received value or nfc.ndef.EncodeError if the assigned value is not a sequence of 16 octets."""

        try:
            if len(self.eir[0x0F]) != 16:
                raise DecodeError("wrong length of simple pairing hash")
            return bytearray(self.eir[0x0F])
        except KeyError:
            return None