protected override void UpdateValueLabel()
        {
            base.UpdateValueLabel();
            DebugUI.HistoryBoolField field = m_Field as DebugUI.HistoryBoolField;
            int historyDepth = field?.historyDepth ?? 0;

            for (int index = 0; index < historyDepth; ++index)
            {
                if (index < historyToggles.Length && historyToggles[index] != null)
                {
                    historyToggles[index].isOn = field.GetHistoryValue(index);
                }
            }
        }