/// <summary>
/// Returns the index immediately after the <see cref="ToolStripItem"/> that
/// was provided to the constructor.
/// </summary>
/// <param name="uiElement"></param>
/// <returns></returns>
protected override int GetInsertingIndex(object uiElement)
{
int index = InternalCollection.IndexOf(item);
if (index < 0)
{
throw new InvalidOperationException();
}
return(index + 1);
}