Hide Report Group Tree in WPF

Using the SAPBusinessObjects.WPF.Viewer.dll, the property ShowGroupTree is not available. To Hide the GroupTree as a default, set the property .ToggleSidePanel to SAPBusinessObjects.WPF.Viewer.Constants.SidePanelKind.None. e.g.

With _viewer
       .IsEnabled = True
       .EnableToolTips = True
       .ShowOpenFileButton = False
       .ShowExportButton = True
       .ShowNextPageButton = True
       .ShowPrevPageButton = True
       .ShowPrintButton = True
       .ShowToggleSidePanelButton = True
       .ShowSearchTextButton = True
       .ToggleSidePanel = SAPBusinessObjects.WPF.Viewer.Constants.SidePanelKind.None
       .ShowRefreshButton = True
       .ShowGoToPageButton = True
       .ViewerCore.ReportSource = _report
      End With