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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 DbGetDeviceAlias(self, argin):
 """ Return alias for device name if found. :param argin: The device name :type: tango.DevString :return: The alias found :rtype: tango.DevString """

        self._log.debug("In DbGetDeviceAlias()")
        ret, dev_name, dfm = check_device_name(argin)
        if not ret:
            th_exc(DB_IncorrectDeviceName,
                  "device name (" + argin + ") syntax error (should be [tango:][//instance/]domain/family/member)",
                  "DataBase::DbGetDeviceAlias()")

        return self.db.get_device_alias(dev_name)