public void ToggleHostMinimized()
{
if( Dispatcher.CurrentDispatcher != Application.Current.Dispatcher ) throw new InvalidOperationException( "This method should only be called by the Application Thread." );
IWindowElement element = _lastFocused;
if( element == null && _dic.Count > 0 ) element = _dic.Keys.FirstOrDefault();
if( element != null )
element.ToggleHostMinimized( HostManipulator );
}