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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 process_npdu(self, npdu):
 """Encode NPDUs from the service access point and send them downstream."""

        if _debug: NetworkAdapter._debug("process_npdu %r (net=%r)", npdu, self.adapterNet)

        pdu = PDU(user_data=npdu.pduUserData)
        npdu.encode(pdu)
        self.request(pdu)