/// <summary>
/// Creates a new <see cref="GUILayoutX"/> and adds it to the field layout.
/// </summary>
/// <param name="index">Index into the GUI layout at which the field layout start at.</param>
/// <returns>Newly created layout.</returns>
public GUILayoutX AddLayoutX(int index)
{
GUILayoutX layout = parentLayout.InsertLayoutX(index + elements.Count);
elements.Add(layout);
return(layout);
}