code: def dump_np_vars(self, store_format='csv', delimiter=','):
          
  
          ret = False
  
          if self.system.files.no_output is True:
              logger.debug('no_output is True, thus no TDS dump saved ')
              return True
  
          if self.write_lst() and self.write_np_dat(store_format=store_format, delimiter=delimiter):
              ret = True
  
          return ret
docs: Dump the TDS simulation data to files by calling subroutines `write_lst` and
          `write_np_dat`.
  
          Parameters
          -----------
  
          store_format : str
              dump format in `('csv', 'txt', 'hdf5')`
  
          delimiter : str
              delimiter for the `csv` and `txt` format
  
          Returns
          -------
          bool: success flag