Helper that retuns a dict of devices for this server.

        :return:
            Returns a tuple of two elements:
              - dict<tango class name : list of device names>
              - dict<device names : tango class name>
        :rtype: tuple<dict, dict>

def get_devices(self):
        """
        Helper that retuns a dict of devices for this server.

        :return:
            Returns a tuple of two elements:
              - dict<tango class name : list of device names>
              - dict<device names : tango class name>
        :rtype: tuple<dict, dict>
        """
        if self.__util is None:
            import tango
            db = tango.Database()
        else:
            db = self.__util.get_database()
        server = self.server_instance
        dev_list = db.get_device_class_list(server)
        class_map, dev_map = {}, {}
        for class_name, dev_name in zip(dev_list[1::2], dev_list[::2]):
            dev_names = class_map.get(class_name)
            if dev_names is None:
                class_map[class_name] = dev_names = []
            dev_name = dev_name.lower()
            dev_names.append(dev_name)
            dev_map[dev_name] = class_name
        return class_map, dev_map