code: def extract(self, cell):
          
          cell = self.cell_dict.get(cell, cell)
          current_library.add(cell)
          current_library.add(cell.get_dependencies(True))
          return cell
docs: Extract a cell from the this GDSII file and include it in the
          current global library, including referenced dependencies.
  
          Parameters
          ----------
          cell : ``Cell`` or string
              Cell or name of the cell to be extracted from the imported
              file.  Referenced cells will be automatically extracted as
              well.
  
          Returns
          -------
          out : ``Cell``
              The extracted cell.