/// <summary>
/// Gets the custom XML from the main document part.
/// </summary>
/// <param name="mainPart">The main document part.</param>
/// <returns>The custom XML as a <see cref="XElement" />.</returns>
public static XElement GetCustomXml(this MainDocumentPart mainPart)
{
CustomXmlPart customXmlPart = mainPart.GetPartsOfType <CustomXmlPart>().FirstOrDefault();
return(customXmlPart == null ? null : customXmlPart.GetXDocument().Root);
}
