docs: def most_recent(adf):
          """
          Looks at each column, and chooses the feed with the most recent data
          point. Honours the Trump override/failsafe logic. """
          # just look at the feeds, ignore overrides and failsafes:
          feeds_only = adf[adf.columns[1:-1]]
  
          # find the feeds with the most recent data...
          feeds_with_data = feeds_only.dropna(how='all')
          selected_feeds = feeds_with_data.T.dropna().index
  
          # if there aren't any feeds, the first feed will work...
          if len(selected_feeds) == 0:
              pre_final = adf['feed001'] # if there all empyty
                                    # they should all be
                                    # equally empty
          else:
              #if there's one or more, take the highest priority one
              pre_final = adf[selected_feeds[0]]
  
  
          # create the final, applying the override and failsafe logic...
          final_df = pd.concat([adf.override_feed000,
                                pre_final,
                                adf.failsafe_feed999], axis=1)
          final_df = final_df.apply(_row_wise_priority, axis=1)
          return final_df