code: def on_menu_previous_interpretation(self, event):
          
          save_current_specimen = self.s
          dlg = wx.FileDialog(
              self, message="choose a file in a pmagpy redo format",
              defaultDir=self.WD,
              defaultFile="thellier_GUI.redo",
              wildcard="*.redo",
              style=wx.FD_OPEN | wx.FD_CHANGE_DIR
          )
          if self.show_dlg(dlg) == wx.ID_OK:
              redo_file = dlg.GetPath()
              if self.test_mode:
                  redo_file = "thellier_GUI.redo"
          else:
              redo_file = None
          dlg.Destroy()
  
          print("redo_file", redo_file)
          if redo_file:
              self.read_redo_file(redo_file)
docs: Create and show the Open FileDialog for upload previous interpretation
          input should be a valid "redo file":
          [specimen name] [tmin(kelvin)] [tmax(kelvin)]