code: def load_raw_arrays(self,
                          columns,
                          start_date,
                          end_date,
                          assets):
          
          country_code = self._country_code_for_assets(assets)
  
          return self._readers[country_code].load_raw_arrays(
              columns,
              start_date,
              end_date,
              assets,
          )
docs: Parameters
          ----------
          columns : list of str
             'open', 'high', 'low', 'close', or 'volume'
          start_date: Timestamp
             Beginning of the window range.
          end_date: Timestamp
             End of the window range.
          assets : list of int
             The asset identifiers in the window.
  
          Returns
          -------
          list of np.ndarray
              A list with an entry per field of ndarrays with shape
              (minutes in range, sids) with a dtype of float64, containing the
              values for the respective field over start and end dt range.