## add(part) {#customxmlpart} Adds an item to the collection. ```Js add(part: Aspose.Words.Markup.CustomXmlPart) ``` | Parameter | Type | Description | | --- | --- | --- | | part | [CustomXmlPart](...... ```js add(part: Aspose.Words.Markup...adds it to the collection. ```js add(id: string, xml: string)...