private static XElement AddProperty(string propertyName, IType propertyType, object value) { var propertyElement = new XElement( ODataService.NsDataServices + propertyName ); if (propertyType.ReturnedClass != typeof(string)) { propertyElement.Add(new XAttribute(ODataService.NsMetadata + "type", LiteralUtil.GetEdmType(propertyType.ReturnedClass))); } string serialized = LiteralUtil.SerializeValue(value); if (serialized == null) { propertyElement.Add(new XAttribute(ODataService.NsMetadata + "null", "true")); } else { propertyElement.Add(new XText(serialized)); } return(propertyElement); }