internal static void ActivateProvider(DockPanelControl panel)
        {
            Type panelType = panel.GetType();
            PropertyProvider provider = GetProvider(panelType);

            if (_activeProvider == provider || provider == null)
                return;

            if (_activeProvider != null)
                _activeProvider.Deactivate();

            _activeProvider = provider;

            if (_activeProvider != null)
                _activeProvider.Activate(panel);

            OnActiveProviderChanged(_activeProvider);
        }