private void OnThreeState(object sender, EventArgs e)
{
if ((_ribbonCheckBox != null) && (_ribbonCheckBox.Ribbon != null))
{
_changeService.OnComponentChanged(_ribbonCheckBox, null, _ribbonCheckBox.ThreeState, !_ribbonCheckBox.ThreeState);
_ribbonCheckBox.ThreeState = !_ribbonCheckBox.ThreeState;
}
}