code: def to_csv(self, path, iamc_index=False, **kwargs):
          
          self._to_file_format(iamc_index).to_csv(path, index=False, **kwargs)
docs: Write timeseries data to a csv file
  
          Parameters
          ----------
          path: string
              file path
          iamc_index: bool, default False
              if True, use `['model', 'scenario', 'region', 'variable', 'unit']`;
              else, use all `data` columns