code: def update_fit_box(self, new_fit=False):
          
          # get new fit data
          if self.s in list(self.pmag_results_data['specimens'].keys()):
              self.fit_list = list(
                  [x.name for x in self.pmag_results_data['specimens'][self.s]])
          else:
              self.fit_list = []
          # find new index to set fit_box to
          if not self.fit_list:
              new_index = 'None'
          elif new_fit:
              new_index = len(self.fit_list) - 1
          else:
              if self.fit_box.GetValue() in self.fit_list:
                  new_index = self.fit_list.index(self.fit_box.GetValue())
              else:
                  new_index = 'None'
          # clear old box
          self.fit_box.Clear()
          # update fit box
          self.fit_box.SetItems(self.fit_list)
          fit_index = None
          # select defaults
          if new_index == 'None':
              self.fit_box.SetStringSelection('None')
          else:
              self.fit_box.SetSelection(new_index)
docs: alters fit_box lists to match with changes in specimen or new/
          removed interpretations
  
          Parameters
          ----------
          new_fit : boolean representing if there is a new fit
  
          Alters
          ------
          fit_box selection and choices, current_fit