internal override XElement CreateXml() { var xRoot = new XElement(XmlConstants.Brick); xRoot.SetAttributeValue(XmlConstants.Type, XmlConstants.XmlChangeVariableBrickType); var xElement = VariableFormula.CreateXml(); xElement.SetAttributeValue(XmlConstants.Category, XmlConstants.VariableChange); var xFormulalist = new XElement(XmlConstants.FormulaList); xFormulalist.Add(xElement); xRoot.Add(xFormulalist); xRoot.Add(UserVariable.CreateXml()); return(xRoot); }