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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 _enable_rpcs(self, conn, services, timeout=1.0):
 """Prepare this device to receive RPCs """


        #FIXME: Check for characteristic existence in a try/catch and return failure if not found

        success, result = self._set_notification(conn, services[TileBusService]['characteristics'][TileBusReceiveHeaderCharacteristic], True, timeout)
        if not success:
            return success, result

        return self._set_notification(conn, services[TileBusService]['characteristics'][TileBusReceivePayloadCharacteristic], True, timeout)