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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 cancelPnLSingle( self, account: str, modelCode: str, conId: int):
 """ Cancel PnLSingle subscription for the given account, modelCode and conId. Args: account: Cancel for this account name. modelCode: Cancel for this account model. conId: Cancel for this contract ID. """

        key = (account, modelCode, conId)
        reqId = self.wrapper.pnlSingleKey2ReqId.pop(key, None)
        if reqId:
            self.client.cancelPnLSingle(reqId)
            self.wrapper.pnlSingles.pop(reqId, None)
        else:
            self._logger.error(
                'cancelPnLSingle: No subscription for '
                f'account {account}, modelCode {modelCode}, conId {conId}')