code: def _show_annotation_box(self, event):
          
          ax = event.artist.axes
          # Get the pre-created annotation box for the axes or create a new one.
          if self.display != 'multiple':
              annotation = self.annotations[ax]
          elif event.mouseevent in self.annotations:
              # Avoid creating multiple datacursors for the same click event
              # when several artists are selected.
              annotation = self.annotations[event.mouseevent]
          else:
              annotation = self.annotate(ax, **self._annotation_kwargs)
              self.annotations[event.mouseevent] = annotation
  
          if self.display == 'single':
              # Hide any other annotation boxes...
              for ann in self.annotations.values():
                  ann.set_visible(False)
  
          self.update(event, annotation)
docs: Update an existing box or create an annotation box for an event.