public string GetVariables()
        {
            string result = string.Empty;

            result += Name + "=" + initialValue.ToString() + Environment.NewLine;
            result += InFlow.GetVariables() + OutFlow.GetVariables();
            return(result);
        }
        public string Render()
        {
            string result = string.Empty;

            if (InFlow == null || OutFlow == null)
            {
                return(result);
            }

            result  = GetVariables();
            result += Name + "'=" + "(" + InFlow.Render() + ")" + "-(" + OutFlow.Render() + ")";

            return(result);
        }