code: def on_enter_specimen(self, event):
          
          new_specimen = self.specimens_box.GetValue()
          if new_specimen not in self.specimens:
              self.user_warning(
                  "%s is not a valid specimen with measurement data, aborting" % (new_specimen))
              self.specimens_box.SetValue(self.s)
              return
          self.select_specimen(new_specimen)
          if self.ie_open:
              self.ie.change_selected(self.current_fit)
          self.update_selection()
docs: upon enter on the specimen box it makes that specimen the current
          specimen