/// <summary>
        /// Register Command unit.
        /// </summary>
        /// <param name="unit">Command unit.</param>
        public void RegisterUnit(ICommandUnit unit)
        {
            if (unit == null || string.IsNullOrEmpty(unit.Code))
            {
                return;
            }

            unit.OnRespondEvent += OnUnitRespond;
            units.Add(unit.Code, unit);
        }
        /// <summary>
        /// Register Command unit.
        /// </summary>
        /// <param name="unit">Command unit.</param>
        public void RegisterUnit(ICommandUnit unit)
        {
            if (unit == null || string.IsNullOrEmpty(unit.Code))
            {
                LogUtility.LogError("Add unit to manager error: The unit or code of unit is null or empty.");
                return;
            }

            unit.OnRespond.AddListener(OnUnitRespond);
            units.Add(unit.Code, unit);
        }