Returns the XML Maps in the file if it has any, or null if there are no XML Maps. Note that the map returned is a copy, so modifying it won't modify the map in the file. To modify the map in the file you need to get it with GetXmlMap, modify it, then set it with SetXmlMap
This method only works for xlsx/m files, not for xls.
function TExcelFile.GetXmlMap: IXmlMap; virtual; abstract;