Mark all devices belonging to a specified device server
        process as non exported

        :param argin: Device server name (executable/instance)
        :type: tango.DevString
        :return:
        :rtype: tango.DevVoid

def DbUnExportServer(self, argin):
        """ Mark all devices belonging to a specified device server
        process as non exported

        :param argin: Device server name (executable/instance)
        :type: tango.DevString
        :return:
        :rtype: tango.DevVoid """
        self._log.debug("In DbUnExportServer()")
        self.db.unexport_server(argin)