code: def set_data_item(self, data_item: DataItem) -> None:
          
          display_panel = self.__display_panel
          if display_panel:
              display_item = data_item._data_item.container.get_display_item_for_data_item(data_item._data_item) if data_item._data_item.container else None
              display_panel.set_display_panel_display_item(display_item)
docs: Set the data item associated with this display panel.
  
          :param data_item: The :py:class:`nion.swift.Facade.DataItem` object to add.
  
          This will replace whatever data item, browser, or controller is currently in the display panel with the single
          data item.
  
          .. versionadded:: 1.0
  
          Scriptable: Yes