code: def update(self, event, annotation):
          
          # Decide whether or not to hide previous highlights...
          for artist in self.highlights.values():
              if self.display == 'multiple':
                  continue
              if self.display == 'one-per-axes':
                  if event.artist.axes is not artist.axes:
                      continue
              artist.set_visible(False)
          self.show_highlight(event.artist)
          DataCursor.update(self, event, annotation)
docs: Update the specified annotation.