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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 decode(self):
 """Hook to transform the response, called when this IOCB is completed."""

        if _debug: IOChainMixIn._debug("decode")

        # refer to the chained iocb
        iocb = self.ioChain

        # if this has completed successfully, pass it up
        if self.ioState == COMPLETED:
            if _debug: IOChainMixIn._debug("    - completed: %r", self.ioResponse)

            # change the state and transform the content
            iocb.ioState = COMPLETED
            iocb.ioResponse = self.ioResponse

        # if this aborted, pass that up too
        elif self.ioState == ABORTED:
            if _debug: IOChainMixIn._debug("    - aborted: %r", self.ioError)

            # change the state
            iocb.ioState = ABORTED
            iocb.ioError = self.ioError

        else:
            raise RuntimeError("invalid state: %d" % (self.ioState,))