docs: def _set_up_savefolder(self):
          """
          Create catalogs for different file output to clean up savefolder.
  
          Non-public method
  
  
          Parameters
          ----------
          None
  
  
          Returns
          -------
          None
  
          """
          if self.savefolder == None:
              return
  
          self.cells_path = os.path.join(self.savefolder, 'cells')
          if RANK == 0:
              if not os.path.isdir(self.cells_path):
                  os.mkdir(self.cells_path)
  
          self.figures_path = os.path.join(self.savefolder, 'figures')
          if RANK == 0:
              if not os.path.isdir(self.figures_path):
                  os.mkdir(self.figures_path)
  
          self.populations_path = os.path.join(self.savefolder, 'populations')
          if RANK == 0:
              if not os.path.isdir(self.populations_path):
                  os.mkdir(self.populations_path)
  
          COMM.Barrier()