code: def asset_open_callback(self, *args, **kwargs):
          
          tf = self.browser.get_current_selection(0)
          if not tf:
              return
          if not os.path.exists(tf.path):
              msg = 'The selected asset does not exist: %s' % tf.path
              log.error(msg)
              self.statusbar.showMessage(msg)
              return
          js = JukeboxSignals.get()
          js.before_open_asset.emit(tf)
          self.open_asset(tf)
          js.after_open_asset.emit(tf)
docs: Callback for the shot open button
  
          :returns: None
          :rtype: None
          :raises: None