docs: def Preview(self, title=None, event=None):
          """ generate Print Preview with wx Print mechanism"""
          if title is None:
              title = self.title
          if self.canvas is None:
              self.canvas = self.parent.canvas
  
          po1  = PrintoutWx(self.parent.canvas, title=title,
                            width=self.pwidth,   margin=self.pmargin)
          po2  = PrintoutWx(self.parent.canvas, title=title,
                            width=self.pwidth,   margin=self.pmargin)
          self.preview = wx.PrintPreview(po1, po2, self.printerData)
  
          if ((is_wxPhoenix and self.preview.IsOk()) or
              (not is_wxPhoenix and self.preview.Ok())):
              self.preview.SetZoom(85)
              frameInst= self.parent
              while not isinstance(frameInst, wx.Frame):
                  frameInst= frameInst.GetParent()
              frame = wx.PreviewFrame(self.preview, frameInst, "Preview")
              frame.Initialize()
              frame.SetSize((850, 650))
              frame.Centre(wx.BOTH)
              frame.Show(True)