public IFluentUnit HasUnits(string unitname)
        {
            IFluentUnit u = new FluentUnit(this._plant, unitname);

            //_message = _message + eq.GetMessage();

            return(u);
        }
        public IFluentUnit HasUnits()
        {
            IFluentUnit u = new FluentUnit(this._plant);

            //_message = _message + eq.GetMessage();

            return(u);
        }