code: def create_data_item(self, title: str=None) -> DataItem:
          
          data_item = DataItemModule.DataItem()
          data_item.ensure_data_source()
          if title is not None:
              data_item.title = title
          self.__document_model.append_data_item(data_item)
          return DataItem(data_item)
docs: Create an empty data item in the library.
  
          :param title: The title of the data item (optional).
          :return: The new :py:class:`nion.swift.Facade.DataItem` object.
          :rtype: :py:class:`nion.swift.Facade.DataItem`
  
          .. versionadded:: 1.0
  
          Scriptable: Yes