C# Extension Methods
/// <summary>
/// Extention Convert XML to Class instance
///
/// Example :
/// RootAreas rootAreas = new RootAreas();
/// rootAreas.ReadXMLFile(ref rootAreas, "AREAS.xml");
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="outputData"></param>
/// <param name="fileName"></param>
/// <summary>
/// Extention Convert XML to Class instance
///
/// Example :
///
/// RootAreas rootAreas = new RootAreas();
/// RootAreas newObject = rootAreas.ReadXMLFile(ref rootAreas, "AREAS.xml"); ///
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="fileName"></param>
/// <returns></returns>