code: def _mouse_handler(self, cli, mouse_event):
          " Click callback. "
          if mouse_event.event_type == MouseEventType.MOUSE_UP:
              self.on_click(cli)
          else:
              return NotImplementef _mouse_handler(self, cli, mouse_event):
          " Click callback. "
          if mouse_event.event_type == MouseEventType.MOUSE_UP:
              self.on_click(cli)
          else:
              return NotImplemented
docs: Click callback.