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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set_data_item(self, data_item: DataItem) -> None: """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 """

        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)